Method and apparatus for sidelink positioning of mobile and static devices

Abstract

Sidelink positioning of user equipment (UE) is supported by exchanging messages between UEs, where the messages include UE sidelink positioning capabilities, sidelink positioning resources, sidelink positioning reference signal configuration, sidelink measurements, and / or location results, and are used to determine the location result. The location results may include range, direction, location, velocity, relative location, and relative velocity. Groups of UEs may be formed for sidelink positioning based on group criteria parameters in a centralized or distributed group management procedure. Group management may remove and add UEs and transfer UEs between groups. Sidelink positioning supported by the network may transfer sidelink positioning messages between UEs and a location server, where the sidelink positioning messages may be embedded in LPP and / or SUPL messages.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 324,123, filed March 27, 2022, entitled "METHODS AND APPARATUS FOR SIDELINK POSITIONING," and U.S. Patent Application No. 18 / 188,914, filed March 23, 2023, entitled "METHODS AND APPARATUS FOR SIDELINK POSITIONING OF MOBILE AND STATIC DEVICES," which are assigned to the assignee of this application and are incorporated by reference in their entireties herein.

[0002] The subject matter disclosed herein relates to wireless communication systems, and more particularly, to systems, methods, and devices that support positioning. [Background technology]

[0003] Wireless communication systems have been widely deployed to provide various telecommunication services such as telephony, video, data, messaging, positioning, and broadcasts. A typical wireless communication system may utilize multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power). Examples of such multiple-access systems include fourth-generation (4G) systems, such as Long-Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth-generation (5G) systems, sometimes referred to as New Radio (NR) systems.

[0004] In some examples, a wireless multiple-access communication system may include several base stations, each simultaneously supporting communication for multiple communication devices, otherwise known as user equipment (UEs). A base station may communicate with a set of UEs on a downlink channel (e.g., for transmissions from the base station to the UEs) and an uplink channel (e.g., for transmissions from the UEs to the base station). Additionally, the UEs may communicate directly with each other using sidelink channels.

[0005] The location of a UE may be useful or necessary for several applications, including emergency calling, navigation, direction finding, asset tracking, and Internet services. For example, in a cellular network, a base station may send a downlink reference signal using which positioning measurements are obtained by the UE and / or the UE may send an uplink reference signal using which positioning measurements are obtained by the base station. The UE may calculate an estimate of its own location using the positioning measurements in UE-based positioning, or may send the positioning measurements to a network entity, e.g., a location server, which may calculate the location of the UE based on the positioning measurements in UE-assisted positioning.

[0006] There are several other applications where the location of a UE or multiple UEs may be required and where traditional UE-based and UE-assisted positioning may not be very useful. Examples of such other applications include vehicle-to-everything (V2X) communication and coordination, public safety first responder scenarios, and control and coordination of automated environments such as factories and warehouses. In these applications, it may be more effective for the UE to communicate using sidelink signaling and for the UE to be located using sidelink-related positioning measurements and / or sidelink-related control signaling. Therefore, support for sidelink-based positioning may be desirable. Summary of the Invention

[0007] Sidelink positioning of user equipments (UEs) is supported by exchanging sidelink positioning messages between the UEs, where the messages may include sidelink positioning capabilities, sidelink positioning resources, sidelink positioning reference signal (PRS) configurations, sidelink measurements, and / or location results for one or more of the UEs and may be used to determine the location result. The location results may include range, direction, location, velocity, relative location, and relative velocity. Groups of UEs may be formed for sidelink positioning based on group criteria parameters used to decide to include or exclude UEs in a group in a centralized or distributed group management procedure. Group management may additionally remove and add UEs and transfer UEs between groups. Sidelink positioning supported by the network may transfer sidelink positioning messages between the UE and a location server, where the sidelink positioning messages may be embedded in LPP and / or SUPL messages.

[0008] An example method for supporting sidelink (SL) positioning of a plurality of other UEs implemented by a user equipment (UE) according to the present disclosure may include sending a first sidelink positioning protocol (SLPP) message to all UEs of the plurality of other UEs. The method may also include receiving a second SLPP message from each UE of the plurality of other UEs, the second SLPP message received from each UE including SLPP capabilities of each UE and SLPP resources of each UE. The method may also include exchanging additional SLPP messages with at least some UEs in the plurality of other UEs, the additional SLPP messages being based on the SLPP capabilities and SLPP resources of each of at least some of the UEs. The method may also include determining a location result for at least some of the UEs based on the additional SLPP message.

[0009] An exemplary user equipment (UE) according to the present disclosure configured to support sidelink (SL) positioning of a plurality of other UEs may comprise a wireless transceiver configured to wirelessly communicate with a network entity, at least one memory, and at least one processor coupled to the wireless transceiver and the at least one memory, where the at least one processor is configured to send a first Sidelink Positioning Protocol (SLPP) message to all UEs of the plurality of other UEs via the wireless transceiver. The one or more processors may be further configured to receive a second SLPP message from each UE of the plurality of other UEs via the wireless transceiver, where the second SLPP message received from each UE includes SLPP capabilities of each UE and SLPP resources of each UE. The one or more processors may be further configured to exchange additional SLPP messages with at least some UEs in the plurality of other UEs via the wireless transceiver, the additional SLPP messages being based on the SLPP capabilities and SLPP resources of each of at least some of the UEs. The one or more processors may be further configured to determine location results for at least some of the UEs based on the additional SLPP messages.

[0010] An example user equipment (UE) in accordance with the present disclosure, the example UE being configured to support sidelink (SL) positioning of a plurality of other UEs, may comprise: means for sending a first Sidelink Positioning Protocol (SLPP) message to all UEs of the plurality of other UEs; means for receiving a second SLPP message from each UE of the plurality of other UEs, the second SLPP message received from each UE including an SLPP capability of each UE and an SLPP resource of each UE; means for exchanging an additional SLPP message with at least some of the plurality of other UEs, the additional SLPP message being based on the SLPP capabilities and SLPP resources of each of the at least some of the UEs; and means for determining a location result for at least some of the UEs based on the additional SLPP message.

[0011] An example method for determining a group of UEs performing sidelink (SL) positioning performed by a user equipment (UE) according to the present disclosure may include discovering a plurality of UEs available for SL positioning, including the UE. The method may also include determining one or more group criteria parameters. The method may also include determining a group status indication for at least one UE in the plurality of UEs based on the one or more group criteria parameters, where the group status indication for the at least one UE indicates inclusion or exclusion of the at least one UE in the group.

[0012] An exemplary user equipment (UE) according to the present disclosure configured to determine a group of UEs performing sidelink (SL) positioning may comprise a wireless transceiver configured to wirelessly communicate with a network entity, at least one memory, and at least one processor coupled to the wireless transceiver and the at least one memory, the at least one processor configured to discover, via the wireless transceiver, a plurality of UEs including the UE that are available for SL positioning. The one or more processors may be further configured to determine one or more group criteria parameters. The one or more processors may be further configured to determine a group status indication for at least one UE in the plurality of UEs based on the one or more group criteria parameters, the group status indication for the at least one UE indicating inclusion or exclusion of the at least one UE in the group.

[0013] An exemplary user equipment (UE) according to the present disclosure, configured to determine a group of UEs that perform sidelink (SL) positioning, may comprise: means for discovering a plurality of UEs that are available for SL positioning, including the UE; means for determining one or more group criteria parameters; and means for determining a group status indication for at least one UE among the plurality of UEs based on the one or more group criteria parameters, where the group status indication for the at least one UE indicates inclusion or exclusion of the at least one UE in the group.

[0014] An example method for enabling a group of UEs including a user equipment (UE) to perform sidelink positioning according to the present disclosure, performed by the UE, may include sending an indication of reverse link communication from each UE in the group to the UE to each of the other UEs in the group. The method may also include receiving an indication of reverse link communication from each UE in the group to each of the other UEs in the group from each of the other UEs in the group. The method may also include determining a group status indication for at least one UE in the group based on the indication of reverse link communication from each UE in the group to the UE and the indication of reverse link communication from each UE in the group to each of the other UEs in the group, where the group status indication for the at least one UE indicates inclusion or exclusion of the at least one UE in the group.

[0015] An exemplary user equipment (UE) according to the present disclosure configured to enable a group of UEs including the UE to perform sidelink positioning may comprise a wireless transceiver configured to communicate wirelessly with a network entity, at least one memory, and at least one processor coupled to the wireless transceiver and the at least one memory, where the at least one processor is configured to send, via the wireless transceiver, to each of the other UEs in the group, an indication of reverse link communication from each UE in the group to the UE. The one or more processors may be further configured to receive, via the wireless transceiver, from each of the other UEs in the group, an indication of reverse link communication from each UE in the group to each of the other UEs in the group. The one or more processors may be further configured to determine a group status indication for at least one UE in the group based on the indication of reverse link communication from each UE in the group to the UE and the indication of reverse link communication from each UE in the group to each other UE in the group, where the group status indication for the at least one UE indicates inclusion or exclusion of the at least one UE in the group.

[0016] An example user equipment (UE) in accordance with the present disclosure, configured to enable a group of UEs including the UE to perform sidelink positioning, may comprise: means for sending to each of other UEs in the group an indication of reverse link communication from each UE in the group to the UE; means for receiving from each of the other UEs in the group an indication of reverse link communication from each UE in the group to each of the other UEs; and means for determining a group status indication for at least one UE in the group based on the indication of reverse link communication from each UE in the group to the UE and the indication of reverse link communication from each UE in the group to each of the other UEs in the group, where the group status indication for the at least one UE indicates inclusion or exclusion of the at least one UE in the group.

[0017] An example method for enabling a first group of UEs including the UE and a second group of UEs including the UE to perform sidelink positioning, performed by a user equipment (UE) according to the present disclosure, may include obtaining location results for a first set of UEs in the first group that do not belong to the second group. The method may also include obtaining location results for a second set of UEs in the second group that do not belong to the first group. The method may also include causing, based on the location results for the first set of UEs and the second set of UEs, to add or transfer at least some of the first set of UEs to the second group, to add or transfer at least some of the second set of UEs to the first group, or both.

[0018] An example user equipment (UE) according to the present disclosure, configured to enable a first group of UEs including the UE and a second group of UEs including the UE to perform sidelink positioning, may comprise a wireless transceiver configured to wirelessly communicate with a network entity, at least one memory, and at least one processor coupled to the wireless transceiver and the at least one memory, where the at least one processor is configured to obtain location results for a first set of UEs in the first group that do not belong to the second group. The one or more processors may be further configured to obtain location results for a second set of UEs in the second group that do not belong to the first group. The one or more processors may be further configured to cause, based on the location results for the first set of UEs and the second set of UEs, to add or transfer at least some of the first set of UEs to the second group, to add or transfer at least some of the second set of UEs to the first group, or both.

[0019] An example user equipment (UE) according to the present disclosure, configured to enable a first group of UEs including the UE and a second group of UEs including the UE to perform sidelink positioning, may comprise: means for acquiring relative locations and velocities of a first set of UEs in the first group that do not belong to the second group; means for acquiring relative locations and velocities of a second set of UEs in the second group that do not belong to the first group; and means for causing an addition or transfer of at least some of the first set of UEs to the second group, an addition or transfer of at least some of the second set of UEs to the first group, or both, based on the relative locations and velocities of the first set of UEs and the second set of UEs.

[0020] An example method implemented by a user equipment (UE) for supporting sidelink (SL) positioning for a group of UEs including the UE according to the present disclosure may include receiving a first SL Positioning Protocol (SLPP) message from a first UE in the group. The method may also include sending the first SLPP message to a location server in a public land mobile network (PLMN). The method may also include receiving a second SLPP message from the location server in response to the first SLPP message. The method may also include sending the second SLPP message to other UEs in the group.

[0021] An exemplary user equipment (UE) according to the present disclosure, configured to support sidelink (SL) positioning for a group of UEs including the UE, may comprise a wireless transceiver configured to wirelessly communicate with a network entity, at least one memory, and at least one processor coupled to the wireless transceiver and the at least one memory, the at least one processor configured to receive a first SL Positioning Protocol (SLPP) message from a first UE in the group via the wireless transceiver. The one or more processors may be further configured to send the first SLPP message to a location server in a public land mobile network (PLMN) via the wireless transceiver. The one or more processors may be further configured to receive a second SLPP message from the location server via the wireless transceiver in response to the first SLPP message. The one or more processors may be further configured to send the second SLPP message to other UEs in the group via the wireless transceiver.

[0022] An exemplary user equipment (UE) in accordance with the present disclosure, configured to support sidelink (SL) positioning for a group of UEs including the UE, may comprise means for receiving a first SL Positioning Protocol (SLPP) message from a first UE in the group, means for sending the first SLPP message to a location server in a public land mobile network (PLMN), means for receiving a second SLPP message from the location server in response to the first SLPP message, and means for sending the second SLPP message to other UEs in the group. [Brief description of the drawings]

[0023] [Figure 1] The architecture of a communication system including several UEs, a Radio Access Network (RAN), and a 5G Core Network (5GC) is shown. [Diagram 2] 1 illustrates a communication system architecture for network supported sidelink positioning. [Diagram 3] 1 is a signal flow showing signaling between a UE and a location server for network supported sidelink positioning. [Figure 4A] FIG. 1 is a block diagram illustrating an implementation of a Sidelink Positioning Protocol (SLPP) message structure. [Figure 4B] FIG. 1 is a block diagram illustrating an implementation of a Sidelink Positioning Protocol (SLPP) message structure. [Diagram 5] 1 is a signal flow showing signaling between a pair of UEs for pair-wise sidelink positioning. [Figure 6A] 13 is a signal flow showing signaling between UEs for sidelink positioning capability exchange, including exchange of capabilities, resources, and service requirements. [Figure 6B] 1 is a signal flow showing signaling between UEs for positioning signal configuration and confirmation exchange. [Figure 6C] 1 is a signal flow showing signaling between UEs for measurement exchange. [Figure 7] 13 is a signal flow illustrating signaling for group operation of sidelink positioning for multiple UEs. [Figure 8] 1 illustrates an environment showing group formation of a sidelink positioning group of UEs. [Figure 9] 13 shows an example of a table of indications of reverse link communication between UEs for a sidelink positioning group. [Figure 10] Indicates the addition or transfer of a UE between sidelink positioning groups of the UE. [Figure 11] FIG. 1 shows a schematic block diagram illustrating certain example features of a UE configured to support sidelink positioning as described herein. [Figure 12] FIG. 1 shows a schematic block diagram illustrating certain example features of a location server configured for network-supported sidelink positioning as described herein. [Figure 13] 1 illustrates a flowchart of an example method for supporting sidelink positioning of a UE, performed by the UE in a manner consistent with disclosed implementations. [Figure 14] 1 shows a flowchart of an example method for determining a group of UEs for performing sidelink positioning, performed by a UE in a manner consistent with disclosed implementations. [Figure 15] 1 shows a flowchart of an example method, performed by a UE, for enabling a group of UEs to perform sidelink positioning in a manner consistent with disclosed implementations. [Figure 16] 1 shows a flowchart of an example method, performed by a UE, for enabling a first group of UEs and a second group of UEs, both of which include the UE, to perform sidelink positioning in a manner consistent with the disclosed implementations. [Figure 17]1 illustrates a flowchart of an example method for supporting sidelink positioning, performed by a UE, in a manner consistent with disclosed implementations.

[0024] Elements are designated in the figures by numerical labels, with like numbered elements in the various figures representing the same or similar elements. Different instances of a common element are designated by following the numerical label of the common element with a letter or hyphen and a second number. For example, multiple instances of element 110 may be designated as 110-1, 110-2, 110-3, etc., or as 110a, 110b, 110c, etc. When referring to such an element using only the first number, it should be understood to be any instance of that element (e.g., element 110 in the previous example refers to elements 110-1, 110-2, and 110-3, or elements 110a, 110b, and 110c). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Techniques and apparatuses for supporting sidelink positioning (SL) between UEs are described herein. The Sidelink Positioning Protocol (SLPP) may be used to support sidelink positioning of UEs in pair-wise positioning, group operation, and network-supported SLPP. Group formation and management in centralized or distributed group management procedures are described, including using group criteria parameters for group formation and indications of reverse link communication between UEs for UE removal from groups, as well as using relative locations, ranges, and velocities of UEs in multiple groups for addition or transfer of UEs between groups. Network-supported sidelink positioning may be enabled by embedding SLPP messages to or from a location server in Long Term Evolution (LTE) Positioning Protocol (LPP) messages, or in both LPP and Secure User Plane Location (SUPL) messages, or by exchanging SLPP messages between the server and the UE that are not embedded in or accompanied by LPP messages.

[0026] The description may, for example, refer to sequences of actions to be performed by elements of a computing device. The various actions described herein may be performed by specific circuitry (e.g., an application specific integrated circuit (ASIC)), by program instructions executed by one or more processors, or a combination of both. The sequences of actions described herein may be embodied in a non-transitory computer-readable medium having stored thereon a corresponding set of computer instructions that, when executed, cause an associated processor to perform the functions described herein. Thus, the various aspects described herein may be embodied in several different forms, all of which are within the scope of the present disclosure, including the claimed subject matter.

[0027] The terms "user equipment" (UE) and "base station" as used herein are not specific or otherwise limited to any particular Radio Access Technology (RAT) unless otherwise stated. Generally, such a UE may be any wireless communication device (e.g., a mobile phone, a router, a tablet computer, a laptop computer, a tracking device, an Internet of Things (IoT) device, an Industrial IoT (IIoT) device, an In Vehicle System (IVS), etc.) used to communicate over a wireless communication network. A UE may be mobile or stationary (e.g., at a particular time) and may communicate with a Radio Access Network (RAN). For example, as used herein, a UE may be an infrastructure node such as a roadside unit (RSU), a Positioning Reference Unit (PRU), etc. As used herein, the term "UE" may be referred to interchangeably as "access terminal" or "AT", "client device", "wireless device", "subscriber device", "subscriber terminal", "subscriber station", "user terminal" or UT, "mobile terminal", "mobile station", RSU, PRU, IVS, or variations thereof. In general, a UE may communicate with a core network via a RAN, through which the UE may be connected to external networks, such as the Internet, and to other UEs. Of course, other mechanisms for a UE to connect to the core network and / or the Internet are contemplated, such as through a wired access network, a Wi-Fi network (e.g., based on IEEE 802.11, etc.), etc.

[0028] Depending on the network in which the base station is deployed, the base station may operate according to one of several RATs while communicating with UEs and may alternatively be referred to as an Access Point (AP), network node, Node B, evolved Node B (eNB), general Node B (gNode B, gNB), etc. Additionally, in some systems the base station may simply provide edge node signaling functionality while in other systems the base station may provide additional control and / or network management functionality.

[0029] A UE may be embodied by any of several types of devices, including, but not limited to, a printed circuit (PC) card, a compact flash device, an external or internal modem, a wireless or wireline phone, a smartphone, a tablet, a tracking device, an asset tag, and the like. A communication link through which a UE can transmit signals to a RAN is called an uplink channel (e.g., a reverse traffic channel, a reverse control channel, an access channel, and the like). A communication link through which a RAN can send signals to a UE is called a downlink channel or a forward link channel (e.g., a paging channel, a control channel, a broadcast channel, a forward traffic channel, and the like). A communication link through which a UE can send signals to other UEs is called a sidelink channel. As used herein, the term traffic channel (TCH) may refer to either an uplink / reverse traffic channel or a downlink / forward or sidelink traffic channel.

[0030] The term "cell" or "sector" as used herein may correspond to one of multiple cells of a base station or to the base station itself, depending on the context. The term "cell" may refer to a logical communication entity used for communication with a base station (e.g., over a carrier) and may be associated with an identifier (e.g., physical cell identifier (PCID), virtual cell identifier (VCID)) to distinguish adjacent cells operating over the same or different carriers. In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., machine-type communication (MTC), narrowband Internet-of-Things (NB-IoT), enhanced mobile broadband (eMBB), or others) that may provide access to different types of devices. In some examples, the term "cell" may refer to a portion (e.g., sector) of a geographic coverage area over which the logical entity operates.

[0031] Standardization of cellular systems and positioning support for cellular systems, such as the Fifth Generation (5G) or New Radio (NR) network systems, is being carried out by the 3rd Generation Partnership Project (3GPP). As an example, standardized RAT-dependent positioning systems include Enhanced Cell ID (E-CID) (using Received Signal Strength (RSS) and Round-Trip Time (RTT), and optionally using Angle of Arrival (AOA)), downlink (DL) positioning such as Observed Time Difference of Arrival (OTDOA) and Downlink Time Difference of Arrival (DL-TDOA), and uplink (UL) positioning such as Uplink Time Difference of Arrival (UL-TDOA) and Uplink Angle of Arrival (UL-AOA). RAT-independent positioning systems undergoing standardization include assisted Global Navigation Satellite System (A-GNSS) and other technologies such as Wireless Local Area Network (WLAN), Bluetooth, Terrestrial Beason System (TBS), and sensor-based positioning including barometric and motion sensors. Additionally, hybrid positioning is undergoing standardization including the use of multiple methods for positioning, e.g., A-GNSS+DL-TDOA hybrid positioning.

[0032] Standardization of sidelink (SL) positioning is also being started in 3GPP. Standardization of SL positioning requires new solutions to define various aspects. For example, standardization of SL positioning may require defining a new sidelink (SL) positioning protocol (SLPP) to be used between UEs and between RSUs and UEs. Note that SLPP messages are also referred to as SL positioning messages in this specification. Furthermore, it may be necessary to define support by location servers, for example, by location management function (LMF) and Secure User Plane Location (SUPL) Location Platform (SLP). Standardization of SL positioning may further require defining means to optimize SL group formation and modification, for example for V2X (including, for example, V2P (Vehicle-to-Pedestrian), V2I (Vehicle-to-Infrastructure), and V2V (Vehicle-to-Vehicle), etc.), to ensure that vehicles in a SL group are generally close to each other and possibly moving in the same direction. In addition, standardization of SL positioning may further require defining suitable procedures and message types for SLPP, allowing new positioning methods and new access types to be added later and supported by the network. Currently, none of the above solutions exist.

[0033] FIG. 1 illustrates an example of a communication system 100 including a first UE 105A, a second UE 105B, a third UE 105C, a Radio Access Network (RAN) 135, here a fifth generation (5G) Next Generation (NG) RAN (NG-RAN), and a 5G Core Network (5GC) 140. The 5GC 140 may be, for example, a Public Land Mobile Network (PLMN). The UEs 105A, 105B, and 105C may be referred to herein individually as UEs 105 or collectively as UEs 105. The UEs 105 may be, for example, an IoT device, a location tracking device, a mobile phone, a vehicle, an On-Board Unit (OBU), or other similar types of devices. The UEs 105 may further be considered as an RSU or a PRU. The 5G network may be referred to as a New Radio (NR) network, the NG-RAN 135 may be referred to as a 5G RAN or an NR RAN, and the 5GC 140 may be referred to as an NG Core network (NGC). The RAN 135 may be another type of RAN, such as a 3G RAN, a 4G Long Term Evolution (LTE) RAN, etc.The communications system 100 may utilize a constellation of satellite vehicles (SVs) 190 that may support a Satellite Positioning System (SPS) (e.g., Global Navigation Satellite System (GNSS)), such as the Global Positioning System (GPS), Global Navigation Satellite System (GLONASS), Galileo, or Beidou, or some other local or regional SPS, such as the Indian Regional Navigational Satellite System (IRNSS), the European Geostationary Navigation Overlay Service (EGNOS), or the Wide Area Augmentation System (WAAS). In some embodiments, the UE 105 may communicate with a RAN node (e.g., gNB 110) or a 5GC 140 node via the SV 190 and an earth station (not shown in FIG. 1), in which case the UE 105 may not communicate directly with the RAN node, but only via the SV 190. This may be used to increase the coverage and / or capacity of the NG-RAN 135. Additional components of the communications system 100 are described below. The communications system 100 may include additional or alternative components.

[0034] 1, the NG-RAN 135 includes NR Node Bs (gNBs) 110a, 110b, and a next generation eNodeB (ng-eNB) 114, and the 5GC 140 includes an Access and Mobility Management Function (AMF) 115, a Session Management Function (SMF) 117, a Location Management Function (LMF) 120, and a Gateway Mobile Location Center (GMLC) 125, a User Plane Function (UPF) 118, and a Secure User Plane Location (SUPL) Location Platform (SLP) 119. The gNBs 110a, 110b, and the ng-eNB 114 are communicatively coupled to one another and are each configured to wirelessly communicate bidirectionally with the UE 105, and are each communicatively coupled to and configured to communicate bidirectionally with the AMF 115 and the UPF 118. The gNBs 110a, 110b, and ng-eNBs 114 may be referred to as base stations (BSs) or RAN nodes. The AMF 115, the SMF 117, the LMF 120, and the GMLC 125 are communicatively coupled to each other, and the GMLC 125 is communicatively coupled to the external client 130. The AMF 115, the SMF 117, the UPF 118, and the SLP 119 are communicatively coupled to each other, and the SLP 119 is communicatively coupled to the external client 130. According to some embodiments, the server 121, the Internet 122, and the server 123 may be communicatively coupled to the UPF 118 to facilitate SL positioning. The SMF 117 may further serve as an initial point of contact for a Service Control Function (SCF) (not shown) that creates, controls, and deletes media sessions.The base stations 110a, 110b, 114 may be macro cells (e.g., high power cellular base stations), or small cells (e.g., low power cellular base stations), or access points (e.g., short-range base stations configured to communicate with short-range technologies such as WI-FI, WI-FI Direct (WiFi-D), BLUETOOTH, Bluetooth-low energy (BLE), ZIGBEE, etc.). One or more of the base stations 110a, 110b, 114 may be configured to communicate with the UE 105 over multiple carriers. Each of the base stations 110a, 110b, 114 may provide communication coverage to a respective geographic area, e.g., a cell. Each cell may be partitioned into multiple sectors depending on the base station antenna.

[0035] 1 provides a generalized view of various components, any or all of which may be utilized as appropriate, and each of which may be duplicated or omitted as necessary. In particular, while only a UE 105 is illustrated, many UEs (e.g., hundreds, thousands, millions, etc.) may be utilized in the communication system 100. Similarly, the communication system 100 may include many more (or fewer) SVs (i.e., more or fewer than the four SVs 190 illustrated), gNBs 110a, 110b, ng-eNB 114, AMF 115, external clients 130, and / or other components. The illustrated connections connecting the various components in the communication system 100 include data and signaling connections, which may include additional (intermediate) components, direct or indirect physical and / or wireless connections, and / or additional networks. Furthermore, the components may be rearranged, combined, separated, substituted, and / or omitted depending on the desired functionality.

[0036] 1 illustrates a 5G-based network, similar network implementations and configurations may be used for other communication technologies such as 3G, Long Term Evolution (LTE), etc. Implementations described herein (whether for 5G technology and / or for one or more other communication technologies and / or protocols) may be used to transmit (or broadcast) directional synchronization signals, receive and measure the directional signals at a UE (e.g., UE 105) or base station 110a, 110b, 114, and / or provide location assistance to the UE 105 (via the LMF 120 or SLP 119 or other location server), and / or calculate a location of one or both of the UEs 105 at a location-enabled device, such as the UE 105, base station 110a, 110b, LMF 120, or SLP 119, based on measurements received at the UE 105 or base station 110a, 110b, 114 for such directionally transmitted signals. The GMLC 125, LMF 120, AMF 115, SMF 117, UPF 118, SLP 119, ng-eNB (eNodeB) 114, and gNBs (gNodeBs) 110a, 110b are examples and may be replaced by or include various other entities including location server functionality and / or base station functionality in various embodiments.

[0037] The communication system 100 is capable of wireless communication in that the components of the system 100 may communicate with each other (at least sometimes using wireless connections) directly or indirectly, for example, via the base stations 110a, 110b, 114 and / or the network 140 (and / or one or more other devices, not shown, such as one or more other base transceiver stations). In the case of indirect communication, the communication may be altered during transmission from one entity to another, for example, to alter header information of the data packets, to change the format, etc. The UE 105 may include multiple UEs and may be a mobile wireless communication device, but may communicate wirelessly and via wired connections. The UE 105 may be any of a variety of devices, such as a smartphone, a tablet computer, a vehicle-based device, etc., although these are merely examples and other configurations of UEs may be used, as it is not required that the UE 105 be any of these configurations. Other UEs may include wearable devices (e.g., smart watches, smart jewelry, smart glasses or headsets, etc.). Still other UEs, whether currently existing or developed in the future, may be used. Additionally, other wireless devices (whether mobile or not) may be implemented within the system 100 and may communicate with each other and / or with the UE 105, the base stations 110a, 110b, 114, the core network 140, and / or the external client 130. For example, such other devices may include IoT or IIoT devices, medical devices, home entertainment and / or automation devices, etc. The core network 140 may communicate with the external client 130, the server 123, or the server 121 (e.g., each of which may be a computer system) to, for example, enable the external client 130, the server 123, or the server 121 to request and / or receive location information regarding the UE 105 (e.g., via the GMLC 125, the SLP 119, or the UPF 118).

[0038] The UE 105 or other device may be configured to communicate in different networks and / or for different purposes and / or using different technologies (e.g., 5G, Wi-Fi communications, multiple frequencies of Wi-Fi communications, satellite positioning, satellite communications, one or more types of communications (e.g., Global System for Mobile Communications (GSM), Code Division Multiple Access (CDMA), Long Term Evolution (LTE)), V2X (e.g., V2P (Vehicle-to-Pedestrian), V2I (Vehicle-to-Infrastructure), V2V (Vehicle-to-Vehicle), etc.), IEEE 802.11p, etc.). V2X communications may be cellular (Cellular-V2X, C-V2X) and / or Wi-Fi (e.g., Dedicated Short-Range Radio Control (DSRC)). The system 100 may be a dedicated short-range connection (DVB-CDMA) or a dedicated short-range connection (DVB-CDMA). The system 100 may support operation on multiple carriers (waveform signals at different frequencies). The multi-carrier transmitter can transmit modulated signals on multiple carriers simultaneously. Each modulated signal may be a Code Division Multiple Access (CDMA) signal, a Time Division Multiple Access (TDMA) signal, an Orthogonal Frequency Division Multiple Access (OFDMA) signal, a Single-Carrier Frequency Division Multiple Access (SC-FDMA) signal, etc. Each modulated signal may be sent on a different carrier and may carry pilot, overhead information, data, etc.The UEs 105 may communicate with each other via inter-UE sidelink (SL) communication by transmitting on one or more sidelink channels, such as a physical sidelink synchronization channel (PSSCH), a physical sidelink broadcast channel (PSBCH), a physical sidelink control channel (PSCCH), a synchronization signal block (SSB), a sidelink channel state information reference signal (SL-CSIRS), a physical sidelink feedback channel (PSFCH), or a sidelink sounding reference signal (SL-SRS).

[0039] The UE 105 may include and / or be referred to as a device, a mobile device, a wireless device, a mobile terminal, a terminal, a mobile station (MS), a Secure User Plane Location (SUPL) Enabled Terminal (SET), or some other name. Further, the UE 105 may correspond to a cell phone, a smartphone, a laptop, a tablet, a PDA, a tracking device, a navigation device, an Internet of Things (IoT) device, an asset tracker, a health monitor, a security system, a smart city sensor, a smart meter, a wearable tracker, or some other portable or movable device. Typically, but not necessarily, the UE 105 may support wireless communications using one or more Radio Access Technologies (RATs), such as Global System for Mobile communication (GSM), Code Division Multiple Access (CDMA), Wideband CDMA (WCDMA), LTE, High Rate Packet Data (HRPD), IEEE 802.11 Wi-Fi (also referred to as Wi-Fi), Bluetooth (BT), Worldwide Interoperability for Microwave Access (WiMAX), 5G New Radio (NR) (e.g., using NG-RAN 135 and 5GC 140), etc. The UE 105 may support wireless communications using, for example, a Wireless Local Area Network (WLAN), which may connect to other networks (e.g., the Internet) using a Digital Subscriber Line (DSL) or packet cable.Use of one or more of these RATs may enable UE 105 to communicate with external clients 130, servers 121, and / or servers 123 (e.g., via elements of 5GC 140 and possibly the Internet 122) and / or enable external clients 130, servers 121, and / or servers 123 to receive location-related information regarding UE 105 (e.g., via GMLC 125, SLP 119, or UPF 118).

[0040] Each of the UEs 105 may comprise a single entity, or may comprise multiple entities, such as in a personal area network where a user may employ audio, video and / or data I / O (input / output) devices and / or body sensors and a separate wireline or wireless modem. An estimate of a UE, e.g., UE 105 location, may be referred to as a location, location estimate, location fix, fix, position, position estimate, or position fix, and may provide location coordinates (e.g., latitude and longitude) of the UE that may or may not include an altitude component (e.g., height above sea level, height or depth above ground, floor level, or basement level). Alternatively, the location of the UE may be represented as a civic location (e.g., as a postal address, or as a designation of some point or small area in a building, such as a particular room or floor). The location of the UE may be represented as an area or volume (defined either geodesically or in urban form) within which the UE is expected to be located with some probability or confidence level (e.g., 67%, 95%, etc.). The location of the UE may be expressed as a relative location, e.g., comprising a distance and a direction from a known location. The relative location may be expressed as relative coordinates (e.g., X, Y (and Z) coordinates) defined relative to some origin in the known location, which may be defined, e.g., geodesically, in terms of cities, or by reference to a point, area, or volume shown, e.g., on a map, floor plan, or building plan. In the description contained herein, use of the term location may include any of these variations unless otherwise indicated.

[0041] When sidelink positioning is used, an absolute (e.g., global) or relative location of the UE may not always be obtained. Instead, location results may be obtained for the UE, which may include a range or distance between the UE and each of one or more other UEs, a direction from the UE to each of the one or more other UEs, a location of the UE relative to the location of some other UEs, a location of the one or more other UEs relative to the location of the UE, a velocity of the UE, and / or a velocity of each of the one or more other UEs. The velocity of a UE may be absolute (e.g., with respect to the Earth) or may be relative to some other UEs, and may be referred to as a "relative velocity." The relative velocity of UE B with respect to another UE A may include a "radial velocity" component, which may be equal to the rate of change of range from UE A to UE B, and a "lateral velocity" component, which may be orthogonal to the radial velocity component as seen by UE A, and may be equal to the angular rate of change of the direction from UE A to UE B multiplied by the range from UE A to UE B. In the description contained herein, use of the term “location result(s)” for sidelink positioning of a UE or group of UEs may include any of these variations, unless otherwise indicated.

[0042] The UE 105 may be configured to communicate with other entities using one or more of a variety of technologies. The UE 105 may be configured to communicate with one or more other UEs (e.g., other UEs 105) via one or more device-to-device (D2D) peer-to-peer (P2P) links. A D2D P2P link may be an example of (or may be supported by) a sidelink, and may be supported with any suitable D2D radio access technology (RAT), such as LTE Direct (LTE-D), Wi-Fi Direct (Wi-Fi D), Bluetooth, etc. One or more of the groups of UEs utilizing D2D communication may be within a geographic coverage area of ​​a Transmission / Reception Point (TRP), such as one or more of the gNBs 110a, 110b, and / or ng-eNB 114. Other UEs in such groups may be outside such geographic coverage areas or may not otherwise be able to receive transmissions from the base station. A group of UEs communicating via D2D communication may utilize a one-to-many (1:M) system in which each UE may transmit to other UEs in the group. The TRP may facilitate scheduling of resources for D2D communication. In other cases, D2D communication may be performed between UEs without the involvement of a TRP. One or more of a group of UEs utilizing D2D communication may be within a geographic coverage area of ​​a TRP. Other UEs in such a group may be outside such geographic coverage area or may not otherwise be able to receive transmissions from a base station. A group of UEs communicating via D2D communication may utilize a one-to-many (1:M) system in which each UE may transmit to other UEs in the group. The TRP may facilitate scheduling of resources for D2D communication. In other cases, D2D communication may be performed between UEs without the involvement of a TRP.

[0043] The base stations (BSs) in the NG-RAN 135 shown in FIG. 1 include NR Node Bs referred to as gNBs 110a and 110b. The pair of gNBs 110a, 110b in the NG-RAN 135 may be connected to each other via one or more other gNBs. Access to the 5G network is provided to the UE 105 via wireless communication between the UE and one or more of the gNBs 110a, 110b, and the gNBs 110a, 110b may provide wireless communication access to the 5GC 140 for UEs using 5G. In FIG. 1, the serving gNB for the UE 105A is assumed to be gNB 110b, while the serving gNB for the UE 105B is assumed to be gNB 110a, although another gNB may act as the serving gNB if the UE 105 moves to another location or may act as a secondary gNB to provide additional throughput and bandwidth to the UE 105, and the UE 105 may share the same serving gNB.

[0044] 1 may include the ng-eNB 114, also referred to as next generation evolved node B. The ng-eNB 114 may be connected to one or more of the gNBs 110a, 110b in the NG-RAN 135, possibly via one or more other gNBs and / or one or more other ng-eNBs. The ng-eNB 114 may provide LTE wireless access and / or evolved LTE (eLTE) wireless access to the UE 105. One or more of the gNBs 110a, 110b and / or ng-eNB 114 may be configured to function as positioning-only beacons that may transmit signals to assist in determining the location of the UE 105, but may not receive signals from the UE 105 or from other UEs.

[0045] The base stations 110a, 110b, 114 may transmit one or more downlink reference signals, including positioning reference signal (PRS) transmissions. The PRS transmissions may be configured for a particular UE 105 to measure and report one or more reporting parameters (e.g., reporting quantities) associated with positioning and location information. The PRS transmissions and reporting parameter feedback may support various location services (e.g., navigation systems, emergency communications). In some examples, the reporting parameters augment one or more additional location systems (e.g., Global Positioning System (GPS) technology) supported by the UE 105.

[0046] The base station 110a, 110b, 114 may configure a PRS transmission on one or more PRS resources of the channel. The PRS resource may span resource elements of multiple physical resource blocks (PRBs) in one or more OFDM symbols of a slot depending on the configured number of ports. For example, a PRS resource may span one symbol of a slot and include one port for transmission. In any OFDM symbol, the PRS resource may occupy consecutive PRBs. In some examples, the PRS transmission may be mapped to consecutive OFDM symbols of a slot. In other examples, the PRS transmission may be mapped to interspersed OFDM symbols of a slot. In addition, the PRS transmission may support frequency hopping within a PRB of a channel.

[0047] One or more PRS resources may span several PRS resource sets according to the PRS resource configuration of the base station 110a, 110b, 114. The structure of one or more PRS resources, PRS resource sets, and PRS resource configurations within a PRS transmission may be referred to as a multi-level resource configuration. For example, the multi-level PRS resource configuration of the base station 110a, 110b, 114 may include multiple PRS resource sets, and each PRS resource set may include a set of PRS resources (e.g., a set of four PRS resources).

[0048] The UE 105 may receive a PRS transmission over one or more PRS resources of the slot. The UE 105 may determine at least one reporting parameter for some of the PRS resources included in the transmission. The reporting parameter for each PRS resource (which may include a reporting quantity) may include one or more of a time of arrival (TOA), a reference signal time difference (RSTD), a reference signal receive power (RSRP), an angle, a PRS identification number, a receive-to-transmit difference (UE Rx-Tx), a signal-to-noise ratio (SNR), or a reference signal receive quality (RSRQ).

[0049] Similarly, the UE 105 may be configured to transmit one or more additional uplink reference signals that may be received by the base stations 110a, 110b, 114 and used for positioning. For example, the UE 105 may transmit a sounding reference signal (SRS) for positioning. The base stations 110a, 110b, 114 that receive the uplink reference signals from the UE 105 may perform positioning measurements such as one or more of time of arrival (TOA), difference between receive and transmit (UE Rx-Tx).

[0050] A UE's location estimate may be determined using reference signals such as PRS signals or SRS for positioning signals or other reference signals from one or more base stations 110a, 110b, 114 or the UE. Positioning methods such as Downlink (DL) Time Difference of Arrival (DL-TDOA), DL Angle of Departure (DL AOD), and Extended Cell ID (ECID) are positioning methods that may be used to estimate a UE's location using reference signals from base stations. For example, DL-TDOA relies on measuring reference signal time differences (RSTDs) between a downlink (DL) signal received from a base station for a reference cell and a DL signal received from a base station for one or more neighboring cells. DL signals from which RTSD may be obtained comprise a Cell-specific Reference Signal (CRS) and a Positioning Reference Signal (PRS).

[0051] Other positioning methods may use reference signals transmitted by the UE, including uplink-based positioning methods and downlink-and-uplink-based positioning methods. For example, uplink-based positioning methods include, for example, UL Time Difference of Arrival (UL-TDOA), UL Angle of Arrival (UL AOA), UL Relative Time of Arrival (UL-RTOA), and downlink-and-uplink-based positioning methods include, for example, Round Trip Time (RTT) with one or more neighbor base stations. Furthermore, sidelink-based positioning may be used, in which the UE transmits and / or receives sidelink positioning reference signals that are measured and used for positioning.

[0052] As noted, while FIG. 1 illustrates nodes configured to communicate according to a 5G communication protocol, nodes configured to communicate according to other communication protocols, such as, for example, an LTE protocol or an IEEE 802.11x protocol, may be used. For example, in an Evolved Packet System (EPS) providing LTE wireless access to the UE 105, the RAN may include an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN), which may include base stations including evolved Node Bs (eNBs). The core network for the EPS may comprise an Evolved Packet Core (EPC). The EPS may include the E-UTRAN plus the EPC, where in FIG. 1, the E-UTRAN corresponds to the NG-RAN 135 and the EPC corresponds to the 5GC 140.

[0053] The gNBs 110a, 110b, and ng-eNBs 114 may communicate with the AMF 115, which in turn communicates with the LMF 120 for positioning functions. The AMF 115 may support mobility of the UE 105, including cell changes and handovers, and may be responsible for supporting signaling connections to the UE 105, and possibly data and voice bearers for the UE 105. The LMF 120 may communicate directly or indirectly with the UE 105, or with the base stations 110a, 110b, 114, for example, through wireless communications. The LMF 120 may support positioning of the UE 105 when the UE 105 accesses the NG-RAN 135 and may support positioning procedures / methods such as Assisted GNSS (A-GNSS), Time Difference of Arrival (TDOA) (e.g., downlink (DL) TDOA or uplink (UL) TDOA), Real Time Kinematic (RTK), Precise Point Positioning (PPP), Differential GNSS (DGNSS), Extended Cell ID (E-CID), Angle of Arrival (AOA), Angle of Departure (AOD), and / or other positioning methods. The LMF 120 may process location service requests for the UE 105, for example, received from the AMF 115 or from the GMLC 125. The LMF 120 may be connected to the AMF 115 and / or to the GMLC 125. A node / system running LMF 120 may additionally or alternatively run other types of location support modules, such as an Enhanced Serving Mobile Location Center (E-SMLC) or a Secure User Plane Location (SUPL) Location Platform (SLP).At least a portion of the positioning functionality (including derivation of the UE's location) may be implemented in the UE (e.g., using signal measurements obtained by the UE for signals transmitted by wireless nodes such as gNBs 110a, 110b and / or ng-eNB 114 and / or assistance data provided to the UE by the LMF 120, for example). At least a portion of the positioning functionality (including derivation of the UE's location) may alternatively be implemented in the LMF 120 (e.g., using signal measurements obtained by gNBs 110a, 110b and / or ng-eNB 114). The AMF 115 may act as a control node that handles signaling between the UE 105 and the core network 140 and provides QoS (Quality of Service) flow and session management. The AMF 115 may support the mobility of the UE 105, including cell changes and handovers, and may be involved in supporting signaling connections to the UE 105.

[0054] The GMLC 125 may support location requests for the UE 105 received from the external client 130 and may forward such location requests to the AMF 115 for forwarding by the AMF 115 to the LMF 120 or may forward the location request directly to the LMF 120. A location response (e.g., including a location estimate or sidelink location result for the UE 105) from the LMF 120 may be returned to the GMLC 125 either directly or via the AMF 115, which may then return a location response (e.g., including a location estimate or sidelink location result) to the external client 130. Although the GMLC 125 is shown connected to both the AMF 115 and the LMF 120, in some implementations only one of these connections may be supported by the 5GC 140.

[0055] The User Plane Function (UPF) 118 may support voice and data bearers for the UE 105 and enable voice and data access of the UE 105 to other networks, such as the Internet 122, and servers, such as server 121 and server 123. The UPF 118 may be connected to the gNB 110 and the ng-eNB 114. The functions of the UPF 118 may include external Protocol Data Unit (PDU) session points of interconnection to data networks, packet (e.g., Internet Protocol (IP)) routing and forwarding, user plane portion of packet inspection and policy rule enforcement, Quality of Service (QoS) handling for the user plane, downlink packet buffering, and triggering of downlink data notifications. The UPF 118 may be connected to the SLP 119 to enable support of positioning of the UE 105 using SUPL. The SLP 119 may further be connected to or accessible from the external client 130.

[0056] As shown, a Session Management Function (SMF) 117 connects the AMF 115 and the UPF 118. The SMF 117 may have the ability to control both the local and central UPFs within a PDU session. The SMF 117 may manage the establishment, modification, and release of PDU sessions for the UE 105, perform IP address allocation and management for the UE 105, act as a Dynamic Host Configuration Protocol (DHCP) server for the UE 105, and select and control the UPF 118 for the UE 105.

[0057] As further shown in FIG. 1, the LMF 120 may communicate with the gNBs 110a, 110b, and / or the ng-eNB 114 using a New Radio Position Protocol A (NRPPa), which may be defined in 3GPP Technical Specification (TS) 38.455. NRPPa messages may be transferred between the gNB 110a (or gNB 110b) and the LMF 220 and / or between the ng-eNB 114 and the LMF 120 via the AMF 115. As further shown in FIG. 1, the LMF 120 and the UE 105 may communicate using the LTE Positioning Protocol (LPP), which may be defined in 3GPP TS 37.355. Here, LPP messages may be transferred between the UE 105 and the LMF 120 via the AMF 115 and the serving gNB 110a, 110b, or the serving ng-eNB 114 for the UE 105. For example, LPP messages may be transferred between the LMF 120 and the AMF 115 using service operations based on the Hypertext Transfer Protocol (HTTP), and may be transferred between the AMF 115 and the UE 105 using 5G Non-Access Stratum (NAS) protocols.

[0058] The LPP protocol may be used to support positioning of the UE 105 using UE-assisted and / or UE-based positioning methods such as A-GNSS, RTK, TDOA, AOA, AOD, and / or E-CID. The NRPPa protocol may be used to support positioning of the UE 105 using network-based positioning methods such as E-CID (e.g., when used with measurements obtained by the gNBs 110a, 110b, or ng-eNB 114) and / or may be used by the LMF 120 to obtain location related information from the gNBs 110a, 110b, and / or ng-eNB 114, such as parameters defining directional Synchronization Signal (SS) transmissions from the gNBs 110a, 110b, and / or ng-eNB 114. The LMF 120 is shown in FIG. 1 as being located in the core network 140, but may be outside the core network 140, e.g., in the NG-RAN. For example, the LMF120 may be co-located or integrated with the gNB, or may be located remotely from the gNB, and may be configured to communicate directly or indirectly with the gNB.

[0059] In a UE-assisted positioning method, a UE, e.g., UE 105A or UE 105B, may obtain location measurements and send the measurements to a location server (e.g., LMF 120) for computation of a location estimate for the UE. For example, the location measurements may include one or more of received signal strength indication (RSSI), round trip signal propagation time (RTT), reference signal time difference (RSTD), reference signal received power (RSRP) and / or reference signal received quality (RSRQ), AOA, AOD for the gNB 110a, 110b, ng-eNB 114, and / or WLAN APs. The location measurements may also or instead include measurements of GNSS pseudorange, code phase, and / or carrier phase for SV 190-193.

[0060] In a UE-based positioning method, a UE, e.g., UE 105A or UE 105B, may obtain location measurements (e.g., which may be the same as or similar to location measurements for a UE-assisted positioning method) and may calculate the location of the UE (e.g., with the help of assistance data received from a location server such as the LMF 120 or broadcast by a gNB 110a, 110b, ng-eNB 114, or other base station or AP).

[0061] In a network-based positioning method, one or more base stations (e.g., gNBs 110a, 110b, and / or ng-eNB 114) may obtain location measurements (e.g., RSSI, RTT, RSRP, RSRQ, AOA, AOD, or time of arrival (ToA) measurements for signals transmitted by a UE, e.g., UE 105A or UE 105B) and / or may receive measurements obtained by the UE. One or more base stations or APs may send the measurements to a location server (e.g., LMF 120) for computation of a location estimate for the UE.

[0062] As mentioned, although the communications system 100 is described with respect to 5G technology, the communications system 100 may be implemented to support other communications technologies, such as GSM, WCDMA, LTE, etc., used to support and interact with mobile devices, such as the UE 105 (e.g., to perform voice, data, positioning, and other functions). For example, in an EPS, the NG-RAN 135 may be replaced with an E-UTRAN including an eNB, and the 5GC 140 may be replaced with an EPC including a Mobility Management Entity (MME) in place of the AMF 115, an E-SMLC in place of the LMF 120, and a GMLC, which may be similar to the GMLC 125.

[0063] Positioning for a UE in a wireless network such as the communication system 100 shown in FIG. 1 typically uses the Uu interface for DL ​​PRS and / or UL PRS, i.e., the air interface between the UE 105 and the radio access network. Positioning for a UE may also or instead use sidelink PRS (SL-PRS), which may be a specific sidelink-defined reference signal for positioning, or may reuse the Uu PRS, e.g., UL PRS, which may be referred to as Sounding Reference Signal for positioning (SRSPos), or other reference signals may be transmitted in a sidelink channel. Sidelink positioning may extend the positioning of a UE by providing additional transmitting (or receiving) nodes. A UE such as UE 105B with a known position may be used to support position determination of another target UE such as UE 105A, and UE 105B may be referred to as an anchor node.

[0064] Using the sidelink positioning method, the UE 105A may transmit, for example, a sidelink PRS or a sidelink SRS signal to be received and measured by another UE 105B. Additionally or alternatively, the UE 105B may transmit, for example, a sidelink PRS or a sidelink SRS signal to be received and measured by the UE 105A. The sidelink PRS may be similar to a PRS (e.g., DL PRS) transmitted by the gNB 110, for example, as described above. The sidelink SRS may be similar to an SRS (e.g., uplink) SRS transmitted by the UE 105 for measurement by the gNB 110, for example, as described above. Measurements of the SL PRS or SL SRS signal may include reception to transmission time difference (Rx-Tx), time of arrival (TOA), reference signal received power (RSRP), reference signal received quality (RSRQ), angle of arrival (AOA), and reference signal time difference (RSTD). SL positioning methods may include SL round-trip signal propagation time (RTT) (also called ranging), SL AOA, and SL AOD.

[0065] In some scenarios, a group of UEs (not shown in FIG. 1 ) may support SL positioning. In this case, one UE in the group may transmit a SL PRS or SL SRS signal that may be measured by some or all of the other UEs in the group. Some or all of the other UEs in the group may also transmit SL PRS or SL SRS signals, respectively, that may be measured by some or all of the other UEs in the group that are different from the UE that transmits the UL PRS or ULSS SRS (e.g., each UE transmits the SL SRS or SL PRS at one or more times that are different from the times that other UEs in the group transmit the SL PRS or SL SRS). Measurements made by the UEs that are applicable to the transmission of the SL PRS or SL SRS by the group of UEs may include Rx-Tx, TOA, RSTD, AOA, RSRP, RSRQ. Positioning methods supported by these measurements may include sidelink RTT (e.g., ranging), sidelink AOA, sidelink AOD, sidelink TDOA (SL-TDOA). Based on the measurements and the positioning method, each UE may determine a location result for itself and / or one or more other UEs in the group. As previously mentioned, the location result for a UE may include the range or distance between the UE and each of the one or more other UEs in the group, the direction from the UE to each of the one or more other UEs in the group, the direction from each of the one or more other UEs in the group to the UE, the location of the UE relative to the location of any other UEs in the group, the location of the UE relative to some other known location, the absolute location of the UE, the velocity of the UE, or the velocity of the UE relative to some other UEs.

[0066] Sidelink positioning may be used for positioning of a UE independent of a core network (e.g., 5GC 140) or a serving PLMN. One example implementation of sidelink positioning may be found in vehicular communication systems such as V2X, which may be used for safety-related applications such as safety warnings, traffic congestion (e.g., automated traffic control), and cooperative or automated vehicle steering. One aspect of sidelink positioning that may require a solution for standardization is the Sidelink Positioning Protocol (SLPP), which may be used between a UE and a location server, including between an RSU and a UE. SLPP may support sidelink positioning, for example, between a UE, an RSU, and a PRU with network access independence. SLPP may provide support for sidelink positioning for pairs of UEs (e.g., ranging), groups of UEs (V2X), and UEs that are members of multiple different groups. As an example, SLPP may provide support for various positioning techniques currently standardized for UE-based and UE-assisted support by location servers (e.g., LMF 120), such as PRS RTT, AOA, Differential AOA (DAOA), AOD, Differential AOD (DAOD), but may also enable support for other PRS and SRS-based positioning methods and non-PRS methods such as RTK later. By allowing the addition of new capabilities and methods later, SLPP may avoid the need to define a separate new positioning protocol that is distinct from SLPP. As an example, additional positioning methods that may be included later in SLPP may include RTK, Wi-Fi, Ultra-Wideband (UWB), BT positioning methods. SLPP may initially enable direct sidelink operation (UEs communicate and coordinate positioning by exchanging SLPP messages using sidelink signaling) and may later be extended to sidelink operation via relays and operation via the network, where UEs may exchange SLPP messages via the network or via intermediate relay UEs.For example, this may be used to coordinate the positioning of two vehicles on a collision course at a corner where direct SL signaling between the two vehicles is not possible. Therefore, SLPP may initially define support for SL PRS-based positioning in a general manner to simplify extension to support for other positioning methods later. For example, SLPP may define general SLPP messages similar to the general LPP messages defined for LPP in 3GPP TS 37.355. SLPP may support separate positioning methods (e.g., SL PRS RTT, SL PRS AOA, SL PRS AOD) using common procedures and common parameters, where feasible. SLPP may define procedures that can be reused for multiple positioning methods and is not limited to just one or a few positioning methods. SLPP may be enabled to be transferred and used by various entities, such as UEs, RSUs, PRUs, and location servers such as LMFs and SUPL SLPs. Location server (e.g., LMF and SUPL SLP) uses may forward SLPP messages within LPP messages to enable UE-assisted positioning by the LMF or SUPL SLP. Alternatively, location server (e.g., LMF and SUPL SLP) uses may forward SLPP messages that are not associated with LPP messages to enable UE-assisted positioning by the LMF or SUPL SLP. SLPP may further support relative (local) and global positioning.

[0067] FIG. 2 illustrates, by way of example, the architecture of a communication system 200 capable of network-supported sidelink positioning. As illustrated in FIG. 2, for sidelink positioning, several UEs may be combined in the same group 210. Within the group 210, there may be various subgroups of UEs. For example, the group 210 of UEs may include a first subgroup 212 of UEs served by a first network (PLMN1 140a), while a second subgroup 214 of UEs is served by a second (different) network (PLMN2 140b), and a third subgroup 216 of UEs is out of coverage and not served by any network. One or more of the UEs served by the network, e.g., the UEs in the subgroup 212 served by PLMN1 140a or the UEs in the subgroup 214 served by PLMN2 140b, may include an RSU.

[0068] Location servers in the serving networks, e.g., LMF1 120a, SUPL SLP1 119a, or Server 1 121a in serving PLMN1 140a, LMF2 120b, SUPL SLP2 119b, or Server 2 121b in serving PLMN2 140b, and Server 3 123 (which communicates to the UEs via PLMN1 140a and / or PLMN2 140b), may support some or all of the UEs in a group served by a network (PLMN), e.g., subgroups 212 and 214, respectively. As shown, the location servers may support the UEs by communicating with the UEs using "LPP / SLPP," which may represent communicating using LPP, SLPP, embedding SLPP in LPP, or a combination thereof. For example, LMF1 120a and LMF2 120b may embed SLPP in the LPP while supporting UEs in subgroups 212 and 214, respectively (e.g., each SLPP message transferred between a UE and LMF1 120a or LMF2 120b may be embedded in one LPP message, and one LPP message may contain one or more embedded SLPP messages). Similarly, SUPL SLP1 119a and SUPL SLP2 119b may embed SLPP in the LPP using an LPP message embedded in a SUPL User Plane Location Protocol (ULP) message while supporting UEs in subgroups 212 and 214, respectively. Additionally or alternatively, LPP and / or SLPP messages may be used and the SLPP message is not embedded in the LPP message (although an LPP message or SLPP message may still be embedded in a SUPL ULP message). Additionally, UEs in each subgroup, and UEs in different subgroups, may exchange SLPP messages with each other to support and coordinate SL positioning.

[0069] Location server (e.g., LMF / SUPL SLP / Server1 / Server2 / Server3) support for a particular UE or UEs may not be visible to other UEs in the group. For example, location server support from PLMN1 140a for UEs in subgroup 212 may not be visible to UEs in subgroup 214 and may not be visible to out-of-coverage UEs in subgroup 216. The support provided by the location server to the UEs may include determining or verifying SL PRS configurations and calculating location results for UEs, including supported and unsupported UEs (e.g., calculating location results for UEs in supported subgroups and for UEs in unsupported subgroups if location information for UEs in unsupported subgroups is provided to the location server). In some implementations, signaling between location servers in separate networks may be used to provide more complete network support. As shown, LMF-LMF or SUPL SLP-SUPL SLP signaling may be used to provide more complete network support (e.g., SLPP in FIG. 2 ). ** An extension to SLPP, called

[0070] SLPP message types may be consistent with LPP message types to allow LPP messages to include embedded SLPP messages and / or to allow SLPP procedures to be consistent with LPP procedures that may reduce implementation and / or testing. Figure 2 shows signaling (e.g., SLPP messages or SLPP messages embedded in LPP messages) between LMF1 120a and one or more of the UEs in subgroup 212, and signaling between LMF2 120b and one or more of the UEs in subgroup 214. Figure 2 also shows LPP messages including SLPP messages, or embedded SLPP messages, embedded in SUPL ULP messages exchanged between SUPL SLP1 119a and one or more of the UEs in subgroup 212, and between SUPL SLP2 119b and one or more of the UEs in subgroup 214. SLPP may include messages similar to the LPP capability request and capability provision messages, which may be referred to, for example, in SLPP as "capability and resource request" and "capability and resource provision." Capability and resource requests / provisions in SLPP may initially be limited to NR SL PRS capabilities and resources, but may later be extended to capabilities and resources for LTE SL PRS, RTK, Wi-Fi, BT, etc.

[0071] In another example, the SLPP may include messages similar to the LPP Assistance Data Provide message, which may be referred to in SLPP as a "positioning signal configuration provide" (or simply as an "assistance data provide"). The positioning signal configuration provide in SLPP may include, for example, the SL PRS configuration to be transmitted by each UE and measured by other UEs, the start time and duration of transmission and the condition for the end of transmission, and one or more of the types of SL PRS measurements requested, such as Rx-Tx, AOA, RSRP, RSRD, TOA, TDOA, etc. In some implementations, the positioning signal configuration provide in SLPP may be extended to define other types of signals, such as RTK signals to be measured, Wi-Fi signals to be transmitted and measured, etc. The positioning signal configuration provide in SLPP may include additional information, for example, to assist the UE in acquiring and measuring signals (e.g., SL PRS signals) and to determine the times of transmission and measurement.

[0072] In another example, SLPP may include messages such as "positioning signal configuration confirm" (or "assistance data confirm provide"), which does not have an analogous LPP message. The positioning signal configuration confirm in SLPP may, for example, confirm whether the positioning signal configuration provide (or assistance data provide) is agreeable. If the positioning signal configuration provide is not (partially) agreeable, a different configuration may be provided as the positioning signal configuration provide. Since LPP does not have an analogous message, a new LPP message type may be added to carry the positioning signal configuration confirm SLPP message when the SLPP message is embedded in the LPP message. However, such a new LPP message type may not be needed when the SLPP message is not embedded in the LPP message.

[0073] In another example, the SLPP may include messages similar to the LPP Provide Location Information messages, which may be referred to, for example, in SLPP as "Provide Location Information" messages. The Provide Location Information messages in SLPP may include and provide SL PRS measurements obtained by the UE for SL PRS transmitted by one or more other UEs, and / or may include and provide location results obtained for the UE and / or other UEs. The Provide Location Information in SLPP may be extended to include and provide other measurements, such as measurements of RTK, Wi-Fi, BT, etc.

[0074] As shown in FIG. 2, UEs in each subgroup and UEs in different subgroups may signal each other using SLPP (e.g., when a UE sends a SLPP message to one or more other UEs). In addition, a location server (e.g., LMF, SUPL SLP, or Servers 1-3) may support UEs using SLPP (as described above). As previously mentioned, according to some embodiments, SLPP may be embedded in LPP, or may be embedded in both LPP and SUPL, or may be sent without being embedded in LPP. Thus, a first UE may receive a first SLPP message from a second UE and may send the first SLPP message to a location server supporting the first UE. The first UE may receive a second SLPP message from the location server in response to the first SLPP message and may send the second SLPP message to the second UE.

[0075] Figure 3 is a signal flow 300 illustrating signaling between UE 105A, UEs 105B, 105C, and 105D, and a location server 302 for network supported sidelink positioning as described herein, by way of example. UEs 105A, 105B, 105C, and 105D may belong to the same group, e.g., UE 105 shown in Figure 1, or any of the UEs shown in network supported subgroups 212 and 214 in Figure 2. Location server 302 may be any of LMF 120, SUPL SLP 119, Server 121, or Server 123 shown in Figure 1, or LMF1 120a or SUPL SLP1 119a shown in Figure 2.

[0076] As shown in FIG. 3, at 310, the UE 105A receives a first sidelink positioning message from the UE 105B. The first sidelink positioning message may be, for example, an SLPP message, as described above, and may be any of the message types described above. The first sidelink positioning message may be sent based on SL multicast (also called SL groupcast) if the group includes more than two UEs, as shown in FIG. 3, or based on SL unicast. In SL multicast (also called SL groupcast), a sidelink positioning message (e.g., an SLPP message) may be transmitted that includes a group destination address (e.g., that may be partially or completely included in a Layer 1 protocol header and / or a Layer 2 protocol header in the sidelink positioning message). Then, a receiving UE (e.g., the UE 105A) that belongs to the group with this group destination address recognizes the group destination address in the sidelink positioning message and receives, decodes, and processes the sidelink positioning message. In SL unicast, the sidelink positioning message may be transmitted including a UE destination address (e.g., a Layer 2 address assigned to UE 105A) and will be received, decoded and processed only by the UE (e.g., UE 105A) whose destination address is included.

[0077] At 320, the UE 105A sends a first LPP / SLPP message (e.g., a first SLPP message or a first SLPP message embedded in an LPP message, as described above) to the location server 302, where the first SLPP message is based on or comprises the first sidelink positioning message.

[0078] At 330, the UE 105A receives a second LPP / SLPP message from the location server 302 in response to the first LPP / SLPP message from 320. The second LPP / SLPP message may be a second SLPP message or a second SLPP message embedded in an LPP message, as described above, and may be any of the message types described above. The second LPP / SLPP message (e.g., the second SLPP message) may include a location result for at least one UE in the group (e.g., UE 105A or UE 105B). For example, the location result for at least one UE in the group may include at least one of a range between the at least one UE and another UE, a direction from the at least one UE to another UE, a location of the at least one UE relative to a location of the other UE, a velocity of the at least one UE, a relative velocity of the at least one UE relative to the velocity of the other UE, or any combination thereof.

[0079] At 340, the UE 105A may send a second sidelink positioning message to one or more of the UEs 105B, 105C, and 105D in the group. The second sidelink positioning message may be a SLPP message and may be based on or include the second SLPP message received at 330. The second sidelink positioning message may be sent based on SL multicast, e.g., as shown in FIG. 3, if the group includes more than two UEs.

[0080] The sidelink positioning messages in the signal flow 300 may be any of the message types as described above. For example, the first sidelink positioning message in 310 and the first LPP / SLPP message in 320 may include sidelink positioning capabilities, sidelink positioning resources, or both for at least one UE in the group, e.g., UE 105B. The first LPP / SLPP message in 320 may include an LPP capability provision message and / or an SLPP capability provision message (e.g., where the SLPP capability provision message may be embedded in the LPP capability provision message). The second LPP / SLPP message in 330 and the second sidelink positioning message in 340 may include sidelink positioning capabilities, sidelink positioning resources, or both for UE 105A. The second LPP / SLPP message in 330 may include an LPP capability provision message and / or an SLPP capability provision message.

[0081] In another example, the first sidelink positioning message at 310 and the first LPP / SLPP message at 320 may include a SL positioning reference signal (PRS) configuration for at least one UE in the group, e.g., UE 105A and / or UE 105B. The first LPP / SLPP message at 320 may include an LPP request assistance data message, an LPP provide assistance data message, an SLPP request assistance data message, and / or a SLPP provide assistance data message (e.g., where SLPP messages may be embedded in the same type of LPP message). The second LPP / SLPP message at 330 and the second sidelink positioning message at 340 may include a SL positioning reference signal (PRS) configuration for at least one UE in the group, e.g., UE 105A or UE 105B. The second LPP / SLPP message at 330 may include an LPP Provide Assistance Data message and / or a SLPP Provide Assistance Data message (eg, where a SLPP Provide Assistance Data message may be embedded in an LPP Provide Assistance Data message).

[0082] In another example, the first sidelink positioning message at 310 and the first LPP / SLPP message at 320 may include sidelink positioning measurements obtained by at least one UE in the group, e.g., UE 105B. The first LPP / SLPP message at 320 may include an LPP Provide Location Information message and / or an SLPP Provide Location Information message (e.g., where the SLPP Provide Location Information message may be embedded in the LPP Provide Location Information message). The second LPP / SLPP message at 330 may include location results for at least one UE in the group, and the second LPP / SLPP message may include an LPP Provide Location Information message and / or an SLPP Provide Location Information message (e.g., where the SLPP Provide Location Information message may be embedded in the LPP Provide Location Information message).

[0083] The location server 302 may be, for example, an LMF or a SUPL SLP. If the location server 302 is a SUPL SLP, the first LPP / SLPP message is sent by the UE 105A to the location server 302 as part of a first SUPL message at 320, and the second LPP / SLPP message is received by the UE 105A from the location server 302 as part of a second SUPL message at 330. The first SUPL message and the second SUPL message may each include a SUPL POS message.

[0084] 4A is a block diagram 400A illustrating, by way of example, one implementation of the structure of a SLPP message 410. As shown, the SLPP message 410 includes a header 412 that may include a session ID, a transaction ID, a sequence number (seq no), an acknowledgment (or acknowledgement) sequence number, and the like. The SLPP message 410 allows for one or more positioning methods or positioning method types. For example, the SLPP message 410 includes as entries a positioning method / type 1 414, a positioning method / type 2 416, and a positioning method / type M 418 (e.g., M may be equal to 3 or more). A positioning method may, for example, use one or more specific signal types (e.g., SL NR PRS, SL LTE PRS, Wi-Fi, or GPS L1-L5) and support one way of determining location for that specific signal type (e.g., one of RTT, AOA, RSRP, or TDOA). On the other hand, a positioning method type uses one or more specific signal types and supports multiple positioning methods for the signal type or types. For example, a positioning method type may use SL PRS signals (e.g., either SL NR PRS signals or both SL NR PRS signals and SL LTE PRS signals) and support multiple positioning methods using these SL PRS signals (e.g., may support all of RTT, AOA, RSRP, and TDOA). Another positioning method type may use GNSS signals and support multiple positioning methods using GNSS signals (e.g., may support GNSS code phase based positioning and GNSS carrier phase based positioning such as RTK).

[0085] The SLPP message 410 may be configured to support a positioning method or method type (also referred to as a positioning type), or both a positioning method and a positioning method type. As shown, each positioning method / type 414, 416, and 418 in the SLPP message 410 may include parameters for each UE in the group, shown as identified by a member ID, e.g., UE1, UE2, ...UEn. It is possible that not all UEs in a group support the same positioning method / type, which may mean that parameters for UEs that do not support a positioning method / type 414, 416, or 418 may not be present for that positioning method / type in the SLPP message 410. Support for multiple positioning methods or method types in the SLPP message 410 may be advantageous when UEs do not all support the same positioning method or method type, e.g., some UEs may support positioning using RTK and SL PRS, while some other UEs only support RTK. However, in some implementations, the SLPP message 410 may provide support for only one positioning method (e.g., NR SL PRS RTT) or one positioning method type (e.g., NR SL PRS).

[0086] Figure 4B is a block diagram 400B illustrating another implementation of the structure of a SLPP message 420. Similar to block diagram 400A of Figure 4A, SLPP message 420 includes a header 422 that may contain information similar to header 412 in Figure 4A. However, now the data may be structured such that each UE in a group of n UEs has separate message portions 424, 426, and 428 in SLPP message 420 that each contain that UE's parameters for each positioning method / type 1-M supported by that UE.

[0087] 5 is a signal flow 500 illustrating, by way of example, signaling between UE 105A and UE 105B for pair-wise sidelink positioning involving only two UEs. UE 105A and UE 105B may be, for example, the UEs shown in FIG. 1 or any two of the UEs shown in group 210 shown in FIG. 2. The sidelink positioning shown in FIG. 5 may be network independent, and thus the UEs shown in FIG. 5 may be out-of-coverage UEs in subgroup 216. The signaling implemented in signal flow 500 may be similar or the same as the SLPP signaling described above with reference to FIG. 2.

[0088] In stage 0 of FIG. 5, UE discovery and establishment of a sidelink communication session or a sidelink positioning session is performed. The discovery process may be request-response or announcement based. The discovery phase may be performed by one or both of the UEs 105A and 105B, for example, to detect other UEs that are available for sidelink positioning. For example, discovery messages may be exchanged between the UEs 105A and / or 105B to determine nearby UEs that are available to participate in sidelink positioning. For example, the UE 105A may broadcast a discovery-based message using sidelink signaling, and the UE 105B may receive and respond to the discovery-based message by sending a similar discovery-based response message back to the UE 105A using sidelink signaling. Additional messages may be exchanged between the UEs 105A and 105B to establish a sidelink communication or positioning session between the UEs 105A and 105B. For example, the UE 105A may send a request to initiate an SLPP positioning session (e.g., an SLPP request) to the UE 105B, and the UE 105B may return a response (e.g., an SLPP response) to the UE 105A agreeing to initiate the SLPP positioning session.

[0089] In stage 1, the UEs 105A and 105B may exchange SLPP capabilities, resources, and service requirements, which may include quality of service (QoS), using, for example, SLPP capability and resource request messages and SLPP capability and resource provision messages, as described above. Exchanging SLPP capabilities, resources, and service requirements may include both the UE 105A and the UE 105B sending their capabilities, resources, and service requirements to the other UE, or only one of the UE 105A or the UE 105B sending its capabilities, resources, and service requirements to the other UE. The capabilities exchanged may define what each of the UEs 105A and 105B is implemented to support. The resources exchanged may define which capabilities each of the UEs 105A and 105B is permitted to support and / or which capabilities each of the UEs 105A and 105B is not permitted to support. The sidelink positioning capabilities that the UE is allowed or not allowed to support may include permissions or restrictions on one or more of the sidelink PRS transmission time, sidelink PRS measurement time, sidelink PRS transmission duration, sidelink PRS measurement duration, bandwidth of sidelink PRS that may be transmitted, bandwidth of sidelink PRS that may be measured, RF frequency of sidelink PRS that may be transmitted, RF frequency of sidelink PRS that may be measured, signal coding of sidelink PRS that may be transmitted, signal coding of sidelink PRS that may be measured, periodicity of sidelink PRS transmissions, periodicity of sidelink PRS to be measured, transmit power for sidelink PRS transmissions, transmit power for sidelink PRS to be measured, or any combination thereof.

[0090] Sidelink positioning capabilities may be fixed and static (e.g., dependent on UE implementation that may never be changed or may be changed infrequently via software upgrades to the UE). Sidelink positioning resources may depend on the spectrum available for SL PRS (e.g., whether PLMN licensed spectrum, unlicensed spectrum or Intelligent Transport System (ITS) spectrum for V2X is available and permitted for use) and / or on existing positioning sessions and / or procedures that the UE may already support or be part of. Existing positioning sessions and / or procedures may mean that the UE cannot transmit and / or measure SL PRS at certain times for a new SL positioning session because at these times the UE needs to have transmitted and / or measured SL PRS for the existing positioning session and / or positioning procedure. Similarly, certain SL PRS characteristics, such as frequencies or coding already used for an existing positioning session, may not be available to be used for a new SL (or SLPP) positioning session. For example, the use of certain SL PRS characteristics for a new positioning session that are already in use for an existing positioning session may prevent the SL PRS transmissions for the new or existing positioning session from being uniquely identified by the UEs involved in the new or existing positioning session, which may then cause errors in location measurements and results. Controlling the use of SL PRS characteristics for the new positioning session by exchanging allowed and / or disallowed sidelink positioning resources may prevent such errors from occurring.

[0091] The service requirements exchanged in stage 1 may include at least one indication of an immediate (e.g., single) location at the current time, a deferred location (e.g., at a later time), a periodic location, a triggered location, a type of location result (e.g., relative location, global location, range, direction), a QoS of the location result (e.g., location result accuracy, location result response time or latency, location periodicity, location reliability), or some combination thereof. The exchanged service requirements may define the type of location (e.g., single or periodic), accuracy, latency, periodicity, reliability that each UE requests or expects in the sidelink positioning session.

[0092] In stage 2, the UE 105A may send a proposed sidelink positioning signal configuration, e.g., PRS1, PRS2 configuration, to the UE 105B, e.g., using a SLPP Positioning Signal Configuration Provide message or a SLPP Assistance Data Provide message, as described above. The PRS1 configuration (in this example) may define the SL PRS to be transmitted later by the UE 105A, and the PRS2 configuration (in this example) may define the SL PRS to be transmitted later by the UE 105B. The PRS1 and PRS2 configurations may be defined and proposed by the UE 105A based on the capabilities, resources, and service requirements exchanged in stage 1, which may include, e.g., the QoS of the UEs 105A and 105B. The PRS1 and PRS2 configurations may be the same or similar to the PRS configurations defined in 3GPP TS 37.355 for LPP, except that they may refer to SL PRS transmission on a sidelink communication channel between the UEs 105A and 105B. For example, the PRS1 and PRS2 configurations may each include specifications for the SL PRS transmission start time, SL PRS transmission duration, SL PRS bandwidth, SL PRS RF frequency (or frequencies), SL PRS signal coding, SL PRS transmission periodicity, SL PRS transmit power, SL PRS muting, and / or SL PRS frequency hopping. Rules and guidelines may be standardized to ensure that the proposed PRS configurations PRS1 and PRS2 are compatible with the capabilities, resources, and service requirements of UEs 105A and 105B, which may include the QoS of both UEs.

[0093] In stage 3, UE 105B may send a message to UE 105A to confirm the proposed positioning signal configuration, e.g., PRS1, PRS2 configuration, using, e.g., SLPP positioning signal configuration confirmation or SLPP assistance data provision confirmation, as described above. In some implementations, UE 105B may instead reject the proposed positioning signal configuration in stage 3, and then UE 105A may propose a different positioning signal configuration until UE 105A confirms the positioning signal configuration. In some implementations, UE 105B may send a modified proposed positioning signal configuration to UE 105A, and UE 105A may confirm the modified positioning signal configuration or send another modified proposed positioning signal configuration to UE 105B. In some implementations, when the PRS1, PRS2 configuration sent in stage 2 is acceptable to UE 105B, stage 3 may be omitted, which may reduce signaling.

[0094] In stage 4, UE 105A transmits SL positioning signals corresponding to the PRS1 configuration, and UE 105B measures these positioning signals (e.g., based on UE 105B's prior knowledge of the PRS1 configuration). UE 105B may, for example, measure one or more of the RTT, Rx-Tx, RSRP, RSRQ, AOA, AOD, and TOA of the PRS1 transmitted by UE 105A.

[0095] In stage 5, UE 105B transmits SL positioning signals corresponding to the PRS2 configuration, and UE 105A measures these positioning signals (e.g., based on UE 105A's prior knowledge of the PRS2 configuration). UE 105A may, for example, measure one or more of the RTT, Rx-Tx, RSRP, RSRQ, AOA, AOD, and TOA of the PRS2 transmitted by UE 105B.

[0096] In step 6, UE 105A and UE 105B exchange measurements obtained in steps 4 and 5. The exchange of measurements may indicate the exact SL PRS configuration to be used in step 4 or step 5 for transmission of the SL PRS, for example, if there was any difference to the PRS1 and / or PRS2 configuration (e.g., with respect to the exact time or duration of the SL PRS transmission), and may further provide the measurements generated in step 4 or step 5. As an example, if the SL positioning signal (SL PRS) transmitted by UE 105A in step 4 that corresponds to the PRS1 configuration sent by UE 105A in step 2 does not exactly match the PRS1 configuration (e.g., because UE 105A slightly delayed the SL PRS transmission because some other UE was transmitting at the transmission time indicated in the PRS1 configuration), UE 105A may include the transmission time actually used by UE 105A in step 4 as part of the measurements sent by UE 105A in step 6. UE 105B may then use the correct transmit time for UE 105A received in step 6 when calculating any location results later (e.g., in step 7). Exchanging measurements in step 6 may include both UE 105A and UE 105B sending their measurements to the other UE, or only one of UE 105A or UE 105B sending their measurements to the other UE.

[0097] In step 7, UE 105A and UE 105B may each calculate a location result, such as a distance and / or direction between UE 105A and UE 105B, a relative location, an absolute location, a velocity, a relative velocity, or any combination thereof, based on the measurements generated in steps 4 and 5 and received in step 6. For example, the UE may determine the range between UE 105A and UE 105B based on the Rx-Tx measurements of the PRS signals, or based on the equivalent TODi and TOAi measurements for the PRSi signals, as follows (i=1 for the PRS transmitted by UE 105A in step 4 and i=2 for the PRS transmitted by UE 105B in step 5, and c represents the speed of transmission of electromagnetic waves, e.g., the speed of light):

number

[0098] The location results determined in step 7 may then be exchanged in step 8. Exchanging location results in step 8 may involve both UE 105A and UE 105B sending their location results to the other UE, or only one of UE 105A or UE 105B sending their location results to the other UE. In the latter case, only the UE that sends its location result to the other UE may calculate its location result in step 7.

[0099] As shown in step 9, steps 4-8 may be repeated as necessary by UE 105A and UE 105B. For example, steps 4-8 may be repeated in step 9 to allow periodic or triggered location results for UE 105A and UE 105B.

[0100] 6A is a signal flow 600 illustrating signaling between UE 105A and UE 105B for sidelink positioning capability exchange, including exchange of capability, resource, and service requirements that may include QoS, which may correspond to stage 1 of FIG. 5. As shown in signal flow 600, in stage 1, UE 105A may send a (e.g., SLPP) capability request message, a (e.g., SLPP) capability provision message, or a (e.g., SLPP) capability, resource, and service requirement provision message that may include QoS to UE 105B. In stage 2, in response to the capability request message, capability provision message, or capability, resource, and service requirement provision message, UE 105B may send a (e.g., SLPP) capability provision message, or a (e.g., SLPP) capability, resource, and service requirement provision message that may include QoS to UE 105A.

[0101] Figure 6B is a signal flow 620 illustrating signaling between UE 105A and UE 105B for positioning signal configuration and confirmation exchange, which may correspond to steps 2 and 3 of Figure 5. As shown, in step 1 of signal flow 620, UE 105A sends a proposed positioning signal configuration, e.g., PRS1, PRS2 configuration, to UE 105B, which corresponds to step 2 of Figure 5 and may be included in a SLPP Provide Assistance Data message or a SLPP Provide Positioning Signal Configuration message. In step 2a, UE 105B may send a configuration confirmation message to UE 105A, which corresponds to step 3 of Figure 5 and may be a SLPP Provide Assistance Data message or a SLPP Provide Assistance Data message. Alternatively, in step 2b, UE 105B may send a configuration reject message to UE 105A, which may be a SLPP Provide Positioning Signal Configuration Reject message or a SLPP Provide Assistance Data Reject message. In response to the configuration reject message from step 2b, UE 105A may prepare another positioning signal configuration, and steps 1 and 2a or 2b are repeated. In another implementation, in step 2c, UE 105B may provide UE 105A with the proposed modified PRS1 configuration, which may be included, for example, in a SLPP Provide Assistance Data message or a SLPP Provide Positioning Signal Configuration message. * , PRS2 *In response to step 2c, UE 105A may send a configuration confirmation message, which may be a SLPP positioning signal configuration confirmation message or a SLPP assistance data provision confirmation message, to UE 105B in step 3. Alternatively, UE 105A may further modify the positioning signal configuration by repeating steps 1 and 2a or 2b.

[0102] Figure 6C is a signal flow 660 illustrating signaling between UE 105A and UE 105B for a measurement exchange, which may correspond to stage 6 of Figure 5. As shown in signal flow 660, in stage 1, UE 105A may send a measurement report to UE 105B, which may include information about the PRS transmitted by UE 105A in stage 4 of Figure 5, such as one or more precise times of transmission, and may further include measurements generated by UE 105A of the PRS transmitted by UE 105B in stage 5 of Figure 5. The measurement report for stage 1 may be a SLPP Location Information Provide message.

[0103] Similarly, in stage 2, UE 105B may send a measurement report to UE 105A, which may include information about the PRS transmitted by UE 105B in stage 5 of Figure 5, such as one or more precise times of transmission, and may further include measurements made by UE 105B of the PRS transmitted by UE 105A in stage 4 of Figure 5. The measurement report for stage 2 may be a SLPP location information provision message.

[0104] Thus, the sidelink positioning message sent by the UE 105A may include the sidelink positioning capabilities and sidelink positioning resources of the UE 105A as described for stage 1 of Figure 5 and as described for stage 1 shown in Figure 6A. The sidelink positioning message may further include the sidelink positioning service requirements of the UE 105A as described for stage 1 of Figures 5 and 6A.

[0105] Additionally, the UE 105A may receive a second sidelink positioning message from the UE 105B. For example, the second sidelink positioning message received from the UE 105B may include the sidelink positioning capabilities and sidelink positioning resources of the UE 105B, as described for step 1 of FIG. 5 and step 2 shown in FIG. 6A. The second sidelink positioning message received from the UE 105B may further include the sidelink positioning service requirements of the UE 105B, as described for step 1 of FIG. 5 and step 2 of FIG. 6A.

[0106] As shown for steps 2-8 of FIG. 5, the UE 105A may exchange additional sidelink positioning messages with the UE 105B, which may be based on the sidelink positioning capabilities and sidelink positioning resources of the UE 105B. Each of the additional sidelink positioning messages may be further based on the sidelink positioning service requirements of the UE 105B. For example, as described for steps 2-8 of FIG. 5 and in signal flows 620 and 660 of FIG. 6B and 6C, the additional sidelink positioning messages exchanged with the UE 105B may include a proposed positioning signal configuration, a confirmation (or rejection or modification) of the proposed positioning signal configuration, a request for measurements and / or measurements of the sidelink positioning PRS, and a location result determined from the measurements of the sidelink positioning PRS.

[0107] As indicated by step 7 of FIG. 5, the UE 105A may determine the location of the UE 105B based on the additional sidelink positioning message.

[0108] The pair-wise sidelink positioning illustrated in Figures 5, 6A, 6B, and 6C may be extended and expanded for group operation, e.g., with a group of UEs, as illustrated by UE group 210 in Figure 2. The group of UEs may, for example, be small enough that direct discovery and direct sidelink signaling is possible between the UEs in the group of UEs. The various sidelink positioning messages transmitted by the UEs in the group may be transmitted using groupcast or multicast, such that each sidelink positioning message is broadcast once to all receiving UEs using sidelink signaling.

[0109] FIG. 7 is a signal flow 700 illustrating signaling for group operation of sidelink positioning for multiple UEs, illustrated as UEs 105A, 105B, 105C, ... 105Z, and sometimes collectively referred to as UEs 105, by way of example. The group of UEs may include a small number of UEs (e.g., up to 20) for which direct discovery and direct SL signaling are possible. The UEs 105 may be, for example, any of the UEs illustrated in FIG. 1 or in the group 210 illustrated in FIG. 2. The sidelink positioning illustrated in FIG. 7 is independent of the network, and thus the UEs illustrated in FIG. 7 may be out-of-coverage UEs in the subgroup 216 of FIG. 2. The signaling performed in the signal flow 700 may be similar or the same as the SLPP signaling described above with reference to FIG. 2 and illustrated in the signal flow 500 of FIG. 5, except that the SLPP signaling may involve a larger number of UEs. If desired, the signaling may be performed directly as illustrated, or via a relay and / or via the network. Note that the number of UEs in signal flow 700 is typically more than two, but may be two in limiting cases (where two of the UEs shown in FIG. 7 are not present).

[0110] In stage 0 of Fig. 7, UE discovery, group formation, and establishment of a multicast sidelink communication session are performed. The discovery process may be request-response or announcement based. The discovery phase may be performed by one or more UEs 105 to detect other UEs 105 that are available for sidelink positioning and suitable to join a group. For example, discovery messages may be exchanged between UEs 105 to determine nearby UEs 105 that are available to participate in sidelink positioning. For example, UE 105A may broadcast a discovery-based message using sidelink signaling, and UEs 105B, 105C, and 105Z may each receive and respond to the discovery-based message by each sending a similar discovery-based response message back to UE 105A using sidelink signaling. The UEs 105 may also exchange (or pre-configure) one or more group criteria parameters for group formation, such as an approximate maximum distance between pairs of UEs (which helps ensure that the UEs 105 can communicate directly with each other), a minimum period of time that any UE 105 may be in communication with other UEs 105 (which helps ensure that the UEs 105 can communicate directly with each other for some minimum period of time), and / or a common direction and / or common speed range of the UEs 105 (which helps ensure that the UEs 105 stay close to each other). Based on the group criteria parameters, the UEs 105 may determine whether to form a group, which UEs 105 should or should not belong to the group, or whether and when additional UEs 105 should be added to the group later, and / or whether and when existing UEs 105 should be removed from the group. For example, the UEs 105 may determine a group status indication for each UE 105 indicating inclusion or exclusion from the group. In FIG. 7, for example, it is assumed that all UEs 105A, 105B, 105C, . . . 105Z meet one or more group criteria and are included in a group.To establish sidelink communications or positioning sessions between the UEs 105, additional messages may be exchanged between the UEs 105. For example, the UE 105A may multicast a single request (e.g., SLPP request) to initiate an SLPP positioning session to the UEs 105B, 105C, and 105Z, and the UEs 105B, 105C, and 105Z may return responses (e.g., SLPP response) to the UE 105A agreeing to initiate the SLPP positioning session.

[0111] In stage 1, the UEs 105 may exchange SLPP capabilities, resources, and service requirements, which may include QoS, using, for example, SLPP capability and resource request messages and SLPP capability and resource provision messages, as described above. The exchange of capabilities, resources, and service requirements, which may include QoS, may be similar to the signal flow 600 shown in FIG. 6A, but with additional UEs. For example, the UEs 105 may exchange capabilities by first each sending a single groupcast SLPP message from each UE 105 to all other UEs 105. The capabilities exchanged may define what each of the UEs 105 is implemented to support. The resources exchanged may define which capabilities each of the UEs 105 is permitted to support and / or is not permitted to support. The sidelink positioning capabilities that the UE is allowed or not allowed to support may include permissions or restrictions on one or more of the following: sidelink PRS transmission time, sidelink PRS measurement time, sidelink PRS transmission duration, sidelink PRS measurement duration, bandwidth of sidelink PRS that may be transmitted, bandwidth of sidelink PRS that may be measured, RF frequency of sidelink PRS that may be transmitted, RF frequency of sidelink PRS that may be measured, signal coding of sidelink PRS that may be transmitted, signal coding of sidelink PRS that may be measured, periodicity of sidelink PRS transmission, periodicity of sidelink PRS that is measured, transmit power for sidelink PRS transmission, transmit power for sidelink PRS that is measured, or any combination thereof. Sidelink positioning capabilities may be fixed and static, as described for stage 1 of FIG. 5. Sidelink positioning resources may depend on the spectrum available for SL PRS and / or on existing positioning sessions and / or positioning procedures that the UE 105 may already support or be part of, as described for stage 1 of FIG. 5. The service requirements of each of the UEs 105 may be as described for stage 1 of FIG.

[0112] In stage 2, the UE 105A may send a proposed positioning signal configuration, e.g., PRS1, PRS2, PRS3, ... PRSn configuration, to the other UE 105B, e.g., using a SLPP positioning signal configuration provision message or a SLPP assistance data provision message, as described above. The PRS1 configuration (in this example) may define the SL PRS to be transmitted later by the UE 105A, the PRS2 configuration (in this example) may define the SL PRS to be transmitted later by the UE 105B, the PRS3 configuration (in this example) may define the SL PRS to be transmitted later by the UE 105C, and the PRSn configuration (in this example) may define the SL PRS to be transmitted later by the UE 105Z, where the PRS1, PRS2, PRS3, and PRSn configurations may be defined and proposed by the UE 105A based on the capabilities, resources, and service requirements exchanged in stage 1, which may include, e.g., the QoS of each of the UEs 105. The PRS1, PRS2, PRS3, and PRSn configurations may be, for example, as described for PRS1 and PRS2, respectively, for stage 2 in FIG.

[0113] In stage 3, each of UEs 105B, 105C, ... 105Z may send a message to UE 105A to confirm the proposed positioning signal configuration, e.g., PRS1, PRS2, PRS3, ... PRSn configuration, using, e.g., SLPP positioning signal configuration confirmation or SLPP assistance data provision confirmation, as described above. In some implementations, UE 105 (e.g., UE 105B) may instead reject the proposed positioning signal configuration in stage 3 and further indicate which PRS configuration is being rejected. UE 105A may then propose a different positioning signal configuration (or simply a different PRS configuration for the rejected PRS configuration) until each of the other UEs 105 confirms the positioning signal configuration. In some implementations, a UE 105 (e.g., UE 105B) may send a modified proposed positioning signal configuration to UE 105A and to other UEs 105 in the group, and UE 105A and the other UEs 105 may confirm the modified positioning signal configuration or send another modified proposed positioning signal configuration to the other UEs 105. In some implementations, the PRS1, PRS2, PRS3, ... PRSn configurations sent in stage 2 may be acceptable to each of UEs 105B, 105C, ... 105Z and may be omitted in stage 3, which may reduce signaling.

[0114] In stage 4, UE 105A transmits SL positioning signals corresponding to the PRS1 configuration, and UE 105B, UE 105C, ... UE 105Z each measure these positioning signals (e.g., based on UE 105B, UE 105C, ... UE 105Z each already knowing the PRS1 configuration). UE 105B, UE 105C, ... UE 105Z may measure, for example, one or more of RTT, Rx-Tx, RSRP, RSRQ, AOA, AOD, TOA of PRS1 transmitted by UE 105A.

[0115] In step 5, UE 105B transmits positioning signal PRS2 and each of the remaining UEs 105 measures positioning signal PRS2 in a similar manner to how they measured PRS1 in step 4.

[0116] In stage 6, the UE 105C transmits a positioning signal PRS3 and the remaining UEs 105 measure the positioning signal PRS3 in a similar manner to how they measure PRS1 in stage 4.

[0117] In step 7, the UE 105Z transmits the positioning signal PRSn and the remaining UEs 105 measure the positioning signal PRSz. similar to how they measured PRS1 in step 4.

[0118] In step 8, the UEs 105 exchange measurements. The measurement exchange may be similar to the signal flow 660 shown in FIG. 6C, but with additional UEs, and the measurements are exchanged, for example, via a single groupcast SLPP message sent by each UE 105 to all other UEs 105 in the group. As described below with reference to FIG. 9, each UE 105 may include an indication of reverse link communications from all other UEs 105 in the group to the UE 105 in the measurements exchanged in step 8. The measurement exchange may, for example, indicate the correct or corrected SL PRS configuration to be used by the UE 105 for transmission of the SL PRS (e.g., as described for step 6 of FIG. 5), and may further provide measurements obtained by the UE 105, for example, in one of steps 4, 5, 6, or 7.

[0119] In step 9, each UE 105 determines a location result, e.g., a distance and / or direction between the UE 105 and each of one or more other UEs 105 in the group, a relative location, an absolute location, a velocity, a relative velocity, or any combination thereof, of one or more of the UEs 105, based on the measurements generated in steps 4-7 and received in step 8. In some embodiments, only one UE 105 (e.g., UE 105A) may determine the location result.

[0120] The location results determined in step 9 may then be exchanged in step 10. Exchanging location results in step 10 may involve each of UEs 105A, 105B, 105C...195Z transmitting its location result to all other UEs 105 in the group, or only one UE 105 (e.g., UE 105A) transmitting its location result to the other UEs 105. In the latter case, only the UEs 105 that transmit their location result to the other UEs 105 may calculate their location result in step 9.

[0121] As shown in step 11, steps 4-10 may be repeated as necessary by UE 105. For example, steps 4-10 may be repeated in step 1 to allow periodic or triggered location results for UE 105A to be obtained.

[0122] Thus, as shown in Fig. 7, when a UE 105, such as UE 105A, belongs to a group of UEs including two or more UEs, the UE 105A may send a sidelink positioning message to all other UEs in the group of UEs, such as UEs 105B, 105C, ... 105Z, for example based on sidelink multicast, so that the sidelink positioning message is broadcast or multicast once to all receiving UEs using SL signaling. For example, as described for step 1 of Fig. 7 and as described for step 1 shown in Fig. 6A, the sidelink positioning message sent by the UE 105A may include the sidelink positioning capabilities and sidelink positioning resources of the UE 105A. The sidelink positioning message may further include the sidelink positioning service requirements of the UE 105A, as described for step 1 of Fig. 7 and Fig. 6A.

[0123] UE 105A may further receive, e.g., based on sidelink multicast, a second sidelink positioning message from each of the other UEs in the group of UEs, e.g., UEs 105B, 105C, ... 105Z, as further described in step 1 of Fig. 7. For example, the second sidelink positioning message received from each of the other UEs may include the sidelink positioning capabilities and sidelink positioning resources of each UE, as described in step 1 of Fig. 7 and step 2 shown in Fig. 6A. The second sidelink positioning message received from each UE may further include the sidelink positioning service requirements of each UE, as described in step 1 of Fig. 7 and Fig. 6A.

[0124] As indicated by steps 2-8 of stage 7, UE 105A may exchange additional sidelink positioning messages with at least some of the UEs in the group of UEs, e.g., UEs 105B, 105C, ... 105Z, e.g., based on sidelink multicast. The additional sidelink positioning messages may, e.g., be based on sidelink positioning capabilities and sidelink positioning resources of each of the at least some of the UEs. Each of the additional sidelink positioning messages may be further based on the sidelink positioning service requirements of UE 1. For example, as described in steps 2-8 of FIG. 7 and in signal flows 620 and 660 of FIG. 6B and FIG. 6C, the additional sidelink positioning messages exchanged with at least some of the UEs may include a proposed positioning signal configuration, may confirm (or reject or modify) the proposed positioning signal configuration, and / or may request or provide measurements of the SL PRS.

[0125] As indicated by stage 9, UE 105A may determine location results for at least some of the UEs based on the additional sidelink positioning messages.

[0126] For group operation of sidelink positioning as shown in Fig. 7, groups of UEs have to be formed first, e.g., based on one or more criteria. Furthermore, modification of group UEs may be necessary when UEs move in and out of a group area.

[0127] Group formation for sidelink positioning may use Proximity-based Services (ProSe), for example, for group discovery and establishment as shown in stage 0 of Fig. 5 and Fig. 7. Various criteria may be used to include UEs in the same group. For example, one criterion for inclusion in a group may be the capability for discovery via ProSe and the capability to communicate directly (via sidelink signaling) with other UEs in the group. Other criteria may include a maximum distance restriction, for example, excluding from the group any UE that is generally farther than a maximum distance threshold from other UEs in the group; a time restriction, for example, excluding from the group any UE that is communicating (or likely to be communicating) with other UEs in the group for less than a minimum duration threshold; and a direction or speed restriction, for example, excluding from the group any UE that is moving in a different direction than other UEs in the group, or at a speed that differs from the speed of other UEs in the group by more than a maximum speed difference threshold. The criteria, for example, thresholds for determining whether a UE meets various requirements for joining a group, may depend on the environment and application. As an example, the distance, time, and direction or speed criteria used in group formation for V2X highway, V2X rural road, or V2X parking lot applications may be different. Once a group is established, periodic ProSe signaling may be used to determine when a UE should leave a group and when a new UE should join a group, for example based on whether group criteria are met. In a group, UEs may be assigned a member ID (e.g., 1, 2, 3, etc.) for identification in the group and in SLPP messages. The group member ID may be used to determine which UE will lead, coordinate, and / or initiate an SLPP positioning session, positioning method, or positioning method type, e.g., which UE will propose a PRS configuration to other UEs, e.g., as shown in stage 2 of Figures 5 and 7. A group may be limited to only one positioning method type (e.g., SL NR PRS), but other positioning method types (e.g., SL LTE PRS or RTK) may be used by different groups.Restricting a group to one positioning method type may avoid scenarios where not all UEs in the group support the same positioning method type and may simplify procedures and messaging. Alternatively, to maximize signaling efficiency, the same group of UEs may employ multiple positioning method types and / or multiple positioning methods, where not all UEs in the group necessarily support the exact same positioning method type or the exact same positioning method.

[0128] Figure 8 illustrates, by way of example, an environment 800 illustrating group formation of sidelink positioning groups of UEs. In the example illustrated in Figure 8, the UEs are on-board units (OBUs) or IVSs for vehicles and are therefore simply illustrated as vehicles. The environment 800 illustrated in Figure 8 may be, for example, a divided four-lane highway and illustrates group membership of UEs with areas having boundaries marked with dotted lines.

[0129] FIG. 8 shows four groups, Group 1, Group 2, Group 3, and Group 4, each including multiple UEs (each UE corresponds to a vehicle). As shown, each UE may belong to one or more groups. A UE's membership in multiple groups may limit the PRS transmission and measurement time in each group to avoid signaling collisions. Various criteria may be used for group formation. For example, each group may be preferably limited to nearby vehicles moving in the same direction. However, as shown in FIG. 8, Group 1 includes one anomaly, UE 802, which is near other vehicles in Group 1 but moving in the opposite direction. In the example of FIG. 8, the environment is a divided highway, and therefore it may not be necessary or desirable to include UE 802 in Group 1 since it is moving in the opposite direction relative to other UEs in Group 1. To avoid anomalies such as those shown in FIG. 8, criteria such as thresholds or requirements for relative distance to other UEs in the group, time period during which the UE is communicating with other UEs in the group, and direction and / or speed of movement may be used for group membership. In other environments, such as, for example, open roads, rural roads, or parking lots, it may be desirable to include UEs traveling in the opposite direction (as well as UEs traveling in the same direction).

[0130] Thus, after discovery of two or more UEs available for sidelink positioning, e.g., as described in step 0 of Figures 5 and 7, the UE may determine (e.g., from preconfigured information in the UE) or obtain (e.g., from the other discovered UEs) one or more group criteria parameters. The UE may determine a group status indication for the at least one UE based on the one or more group criteria parameters generated or obtained from the one or more other UEs. The group status indication may, for example, indicate the inclusion or exclusion of the at least one UE in a group.

[0131] In some implementations, group management may be centralized, e.g., performed by one UE, e.g., UE 105A shown in Figures 5 and 7. With centralized group management, other UEs, e.g., any of UEs 105B, 105C, ... 105Z in Figure 7, may be included in the group when UE 105A determines that a group status indication for the other UE indicates inclusion of the other UE in the group. Similarly, with centralized group management, other UEs, e.g., any of UEs 105B, 105C, ... 105Z, may be excluded from the group when UE 105A determines that a group status indication for the other UE indicates exclusion of the other UE from the group.

[0132] In some implementations, group management may be distributed, e.g., performed by all UEs, e.g., UEs 105A and 105B shown in FIG. 5, or UEs 105A, 105B, 105C, ... 105Z shown in FIG. 7. In distributed group management, for example, each UE determines a group status indication for each of the other UEs based on group criteria parameters generated or obtained from the other UEs. A UE may be included or excluded from a group based on the group status indication for the UE determined by each of the other UEs. For example, if all or most of the other UEs determine that a particular UE 105 should be included in the group, the UE 105 may be included. Similarly, if all or most of the other UEs determine that a particular UE 105 should be excluded from the group, the UE 105 may be excluded. If each UE sends its determined group status indication to all other UEs, then each UE may determine for itself whether it is to be included in or excluded from the group based on whether all or most of the group status indications for each UE determined by the other UEs indicate inclusion or exclusion.

[0133] As discussed above, the criteria parameters for inclusion in a group may include one or more of a distance limit or threshold, a time limit or threshold, a movement direction limit or threshold, and a speed (or speed difference) limit or threshold. The distance limit or threshold may, for example, limit inclusion in a group to UEs that are less than a threshold distance from other UEs in the group. In some implementations, the threshold distance may be with respect to any UE in the group or may be with respect to an average location of the group, e.g., the average UE location, center of gravity, centroid (or other single location) of the group. The threshold distance may vary based on the environment, including the type of road, road conditions, day of the week, time of day, traffic conditions, weather conditions, etc. For example, a relatively large threshold distance (e.g., 100-500 meters) may be used in an environment with higher speeds (e.g., highways) or fewer restrictions on movement direction (e.g., no road division), while a relatively small threshold distance (e.g., 20-100 meters) may be used in an environment with lower speeds (parking lots) or more restrictions on movement direction (e.g., divided roads).

[0134] Another criterion may be a time limit or threshold, for example, inclusion in a group may be limited to UEs that have been communicating (or may be communicating) with other UEs in the group for longer than a threshold time. For example, a UE may be near other UEs in the group, but may be moving in a different direction or on a different road, and thus only communicate with UEs in the group momentarily. The expected time that a UE will be communicating with UEs in a group may be determined based on various factors, such as the location for the UE, the direction of movement, the number and density of UEs. The threshold time may be based on the environment, including the type of road, road conditions, traffic conditions, weather conditions, etc. For example, a relatively small time threshold (e.g., 5 seconds) may be used in a higher speed environment (e.g., highways), and a relatively large time threshold (e.g., 30 seconds) may be used in a lower speed environment (parking lots and local roads).

[0135] Another criterion may be a movement direction restriction or threshold, which may limit inclusion in a group to UEs based on UEs moving in the same or similar direction on the same road as the UEs in the group. The criterion for movement direction restriction may be based on the environment, including, for example, the type of road, road conditions, traffic conditions, weather conditions, etc. For example, the criterion for movement direction restriction may be given more weight, for example, to consider UEs for inclusion in a group in an environment where the likelihood of a collision is increased. For example, in an environment with divided roads, a head-on collision is not usually possible, and a high weight may be given to the movement direction restriction. In an environment where the likelihood of a head-on collision or a side collision is higher, for example, an undivided road, an intersection, or a parking lot, the movement direction restriction may be given a lower weight or may be removed (e.g., so that UEs may be in the same group regardless of their movement direction).

[0136] Another criterion may be a speed or speed difference limit or threshold, which may limit inclusion in a group of UEs to UEs having a speed that is less than a threshold difference from one or more of the speeds of other UEs in the group. In some implementations, the speed limit may be with respect to the average speed of the UEs in the group, or with respect to the speed of one particular UE in the group, or with respect to the speed of each UE in the group. The threshold difference may vary based on the environment, including the type of road, road conditions, traffic conditions, weather conditions, etc. For example, a relatively high threshold difference (e.g., 50 km / hr) may be used in higher speed environments (e.g., highways), while a relatively low threshold difference (e.g., 20 km / hr) may be used in lower speed environments (e.g., parking lots and rural roads) or environments where platooning is used.

[0137] Additional or other criteria parameters for inclusion in a group may be used. For example, in some implementations, the group criteria parameters may include a sidelink positioning method restriction or a sidelink positioning method type restriction. For example, a sidelink positioning method restriction may limit inclusion in a group of UEs to UEs that support the same sidelink positioning methods as other members of the group. The sidelink positioning methods may be restricted, for example, to one or more specific signal types (e.g., SL NR PRS, Wi-Fi, GPS L1-L5) or to one specific positioning method (e.g., SL NR PRS RTT). A sidelink positioning method type restriction may limit inclusion in a group of UEs to UEs that support the same sidelink positioning method types as other members of the group. The sidelink positioning method types may be restricted, for example, to one or more specific signal types (e.g., SL NR PRS, Wi-Fi, GPS L1-L5). Restricting a group of UEs to support one or more common sidelink positioning methods or one or more common sidelink positioning method types may simplify the sidelink positioning procedures and messaging. For example, Figures 5 and 7 may assume that all participating UEs 105 support a common sidelink positioning method type based on transmission and measurement of SL PRS. If some of the participating UEs 105 do not support transmission and measurement of SL PRS, the signaling and procedures of Figures 5 and 7 may not be possible and a different, more complex positioning procedure may be required to obtain location results for all participating UEs 105.

[0138] Once a group of UEs is formed, it may be necessary to update the group, e.g., to remove or add UEs to the group. For example, in V2X applications, group membership changes may sometimes be required quickly, e.g., within a matter of seconds. The exchange of measurements and / or location results using SLPP, e.g., shown in steps 6 and 8 of FIG. 5 and steps 8 and 10 of FIG. 7, and the reception and measurement of PRS, e.g., shown in steps 4 and 5 of FIG. 5 and steps 4-7 of FIG. 7, allow each UE to know whether reverse link communication still exists with each of the other UEs in the group. In a decision labeled D1 here, the UE 105 may determine (e.g., in steps 6 or 8 of FIG. 5 or steps 8 or 10 of FIG. 7) whether the UE 105 is able to receive and decode SLPP messages sent by other UEs. In another determination, labeled here as D2, the UE 105 may determine (e.g., in steps 4 or 5 of FIG. 5 or one of steps 4-7 of FIG. 7) whether the UE 105 is able to receive and measure the SL PRS transmitted by the other UE. In some embodiments, the UE 105 may determine that reverse link communication from another UE 105 exists only if both D1 and D2 are determined to be true. In other embodiments, the UE 105 may determine that reverse link communication from another UE 105 exists if either D1 or D2 are determined to be true. In yet another embodiment, the UE 105 may determine that reverse link communication from another UE 105 exists only if D1 is determined to be true (or if and only if D2 is determined to be true).

[0139] The UE may then indicate its reverse link communication decision to all other UEs in the group, e.g., using a bit string, in the SLPP messages used to exchange measurement or location results, e.g., as shown in steps 6 and 8 of Figure 5 and steps 8 and 10 of Figure 7. For example, UE 105A in Figure 7 may send a reverse link communication decision to the other UEs 105 in Figure 7 indicating whether the UE 105 has determined that there is reverse link communication (to UE 105A) from each of UE 105B, UE 105C, and UE 105Z. Thus, each UE may then build a table indicating the reverse link communication status between all pairs of UEs, which may then be used to determine a group status indication for each UE in the group, and which may then be used to determine whether to retain each UE in the group or to remove one or more UEs from the group.

[0140] In some embodiments, a UE may not explicitly indicate its reverse link communication decision to other UEs (e.g., in step 8 of FIG. 7), but may implicitly indicate its reverse link communication decision to other UEs in the group. The implicit indication may correspond to the provision of measurements for other UEs. In a measurement report message sent by UE A to other UEs in the group (e.g., in step 8 of FIG. 7 or steps 1 or 2 of FIG. 6C), the inclusion of one or more measurements obtained by UE A for a SL PRS transmitted by another UE B may be assumed to imply that there is a reverse link communication from the other UE B to UE A. Conversely, the exclusion of measurements obtained by UE A for a SL PRS transmitted by another UE B, or an indication that UE A could not obtain any measurements for a SL PRS transmitted by the other UE B, may be assumed to imply that there is no reverse link communication from the other UE B to UE A.

[0141] 9 illustrates an example of a table 900 that may be generated by a UE (e.g., UE1) for a group of UEs labeled, for example, UE1, UE2, UE3, UE4, and UE5 and used to determine to remove a UE from the group. The entries in table 900 may be based on indications of reverse link communications between the UEs, indicating whether each column-wise UE has determined (e.g., indicated) that reverse link communications exist (and thus signals may be received) from each row-wise UE with a possible Y (yes), N (no), or U (unknown) entry. In the example shown in FIG. 9, UE1 knows that reverse link communications exist (i.e., signals may be received) from UE2, UE3, and UE4, as indicated by the Ys in the rows for UE2, UE3, and UE4 and the column for UE1 of table 900, but knows that no reverse link communications exist (i.e., no signals are received) from UE5, as indicated by the Ns in the row for UE5 and the column for UE1 of table 900. Further, UE2, UE3, and UE4 may each indicate to all other UEs in the group (including UE1) in the measurement or location result exchange (e.g., step 8 or 10 of FIG. 7) that they have determined that there is reverse link communication from each other (i.e., they can receive signals), as indicated by Y in the columns for UE2, UE3, and UE4 and rows for UE1, UE2, UE3, and UE4 in table 900, but not from UE5, as indicated by N in the row for UE5 in table 900. UE1 does not receive a message from UE5, and thus UE1 does not know whether UE5 receives signals from UE1, UE2, UE, or UE4, as indicated by U in the column for UE5 in table 900. UE5 is therefore a candidate for removal from the group. The ProSe layer or group support layer may be periodically invoked to remove a UE (e.g., UE5 in this example) from the group based on such reverse link communication determination.

[0142] Thus, after the formation of the group, a UE, e.g., UE 105A shown in FIG. 7, may send an indication of reverse link communication from each of the other UEs in the group to UE 105A to each of the other UEs in the group, e.g., UEs 105B, 105C, ... 105Z, e.g., as shown in the measurement report in the exchanged measurement step 8 of FIG. 7 and step 1 of FIG. 6C. The indication of reverse link communication may be sent based on sidelink multicast, e.g., when the group includes more than two UEs. UE 105A may further receive an indication of reverse link communication from each of the other UEs in the group to each of the other UEs in the group in the exchanged measurement step 8 of FIG. 7 and in the measurement report in step 2 of FIG. 6C from each of the other UEs in the group. The indication of reverse link communication from any UE in the group to any other UE in the group may indicate whether sidelink positioning signaling (e.g., SLPP message, sidelink PRS, or both) transmitted by any UE was or was not received by any other UE. UE 105A may determine a group status indication for one or more UEs in the group based on the indication of reverse link communications from each UE in the group to UE 105 and the indication of reverse link communications from each UE in the group to each of the other UEs in the group. The group status indication for at least one UE may indicate inclusion or exclusion of at least one UE in the group.

[0143] In some implementations, the UE 105A may determine a status of forward link communication and a status of reverse link communication between all pairs of UEs in the group based on an indication of reverse link communication from each UE in the group to the UE 105A and an indication of reverse link communication from each UE in the group to each other UE in the group. The forward link communication may be the opposite of the reverse link communication. For example, if reverse link communication from UE B to UE A is determined by UE A to exist, then forward link communication from UE B to UE A exists. The UE 105A may determine a group status indication for at least one UE based on the status of forward link communication and the status of reverse link communication between all pairs of UEs in the group. The forward link communication status and reverse link communication status between any pair of UEs A and B in the group may indicate, for each of the forward transmission direction (e.g., from UE A to UE B) and reverse transmission direction (e.g., from UE B to UE A), whether successful sidelink positioning signaling transmission between the pair of UEs A and B is currently possible, is currently not possible, or has an unknown status, e.g., as shown in FIG. 9.

[0144] In some implementations, group management may be centralized, e.g., performed by one UE, e.g., UE 105A in the examples shown in Figures 5 and 7, or UE 1 in the example shown in Figure 9. With centralized group management, another UE, e.g., any of UEs 105B, 105C, ... 105Z, may be included in the group when the UE (e.g., UE 105A or UE 1) determines that a group status indication for the other UE indicates the inclusion of the other UE in the group. Similarly, with centralized group management, another UE, e.g., any of UEs 105B, 105C, ... 105Z, may be excluded from the group when the UE (e.g., UE 105A or UE 1) determines that a group status indication for the other UE indicates the exclusion of the other UE from the group.

[0145] In some implementations, group management may be distributed, e.g., performed by all UEs, e.g., UEs 105A and 105B shown in FIG. 5, or UEs 105A, 105B, 105C, ... 105Z shown in FIG. 7, or UE1, UE2, UE3, UE4, UE5 in the example shown in FIG. 9. In distributed group management, for example, each UE determines a group status indication for all UEs based on an indication of reverse link communications determined by (e.g., received from) all UEs in the group. UEs may be included or excluded from a group based on a group status indication for the UE determined by the UE itself or determined by one or more of the other UEs in the group.

[0146] In addition to removing UEs from a group, it may also be necessary to update a group by adding new UEs. In some situations, it may be desirable to merge two or more groups of UEs into a single group, or to add one or more members from another group to a group. For example, a UE that is a member of two or more groups may use the relative locations and velocities of the UEs in the groups, which may be used to infer the future relative locations of the UEs, to determine when two groups may be merged, or when a UE from one group may be added or transferred to another group.

[0147] FIG. 10 illustrates an environment 1000 showing the addition or transfer of UEs between sidelink positioning groups of UEs, including group 1 and group 2, shown as regions with dotted borders, as an example. As with FIG. 8, in the example shown in FIG. 10, the UEs are vehicular OBUs or IVSs and are therefore simply shown as vehicles. In the example shown in FIG. 10, UE1 and UE2 in group 1 may be candidates for addition to group 2. UE3 belongs to both group 1 and group 2 and therefore knows the relative location and speed and signaling connectivity of UE1 and UE2, and can determine that UE1 and UE2 should be added to group 2 based on the relative location and speed and signaling connectivity. The SLPP layer in UE3 may notify the ProSe layer or application layer in UE3 to trigger group reconfiguration. In another implementation, the SLPP layer of each UE periodically reports the relative UE location, speed, and signaling connectivity to the ProSe layer or application layer to trigger group reconfiguration by the ProSe layer or application layer. Use of SLPP may advantageously reduce ProSe layer or application layer signaling and / or latency that would otherwise be required for group reconfiguration.

[0148] Thus, a UE belonging to two different groups of UEs, such as UE3 in the example of Figure 10, may obtain the relative location and velocity of a first set of UEs in the first group and may obtain the relative location and velocity of a second set of UEs in the second group. Based on the relative locations and velocities of the first set of UEs and the second set of UEs, the UE may cause the addition or transfer of at least some of the first set of UEs to the second group, or the addition or transfer of at least some of the second set of UEs to the first group, or both. For example, in one implementation, the addition or transfer of at least some of the first set of UEs or at least some of the second set of UEs may merge the first group with the second group.

[0149] The UE 105 may include a Discovery (DSC) service layer, which may be defined by 3GPP. Services provided by the DSC service layer to higher layers may include determining or obtaining unique IDs of discovered nearby UEs, services supported by each nearby UE (including, for example, sidelink positioning), approximate range / direction to each nearby UE, and location / velocity of each nearby UE. Services provided by the DSC service layer to higher layers may also include establishing a communication channel, connection, or session to each nearby UE. Services requested by higher layers from the DSC service layer may include (i) discovery of nearby UEs and attributes of discovered UEs that need to be determined or obtained, (ii) willingness to be discovered by other UEs and attributes of UEs to be provided to other UEs for discovery, and (iii) requests or authorizations to receive / provide supported services, receive / provide approximate range / direction, receive / provide location / velocity, and establish communication channels / connections / sessions. Services implemented by higher layers based on the DSC service layer support may include ranging between two UEs using SLPP and forming a group of UEs.

[0150] The UE 105 may include a Group Support (GS) service layer, which may be defined by 3GPP. The GS service layer may be used to help manage groups of UEs, but group membership decisions may not be made by the GS service layer, but only by higher layers (e.g., application layers). The GS service layer may not be needed for ranging or other services between only pairs of UEs. The GS service layer may support, for example, groups of more than two UEs. Services provided by the GS service layer to higher layers may include: (i) creating a group of UEs, given UE IDs, pair-wise communication channels, group member IDs, member priorities, and group leader, (ii) creating a multicast channel / connection / session for a group of UEs, where one message from any UE can be multicast to all other UEs in the group, (iii) creating and providing group IDs and group member IDs to higher layers, (iv) managing the addition of new UEs to a group and the removal of existing UEs from a group, (v) managing group splits and merges, and (vi) managing communication resources, e.g., licensed / unlicensed spectrum. Decisions regarding group membership and group changes may be made by higher layers. Services requested by higher layers to the GS service layer may include: (i) creating a group of UEs (e.g., using a UE ID and a pair-wise communication channel); (ii) removing a UE (for the GS service layer) from the group of UEs; (iii) removing another UE from the group of UEs; (iv) adding another UE to the group of UEs; (v) splitting the group of UEs into two separate groups; and (vi) merging two groups of UEs into one group.

[0151] The UE 105 may include a sidelink positioning service layer, also referred to as SL positioning layer, SLPP service layer, or SLPP layer, which may be defined by 3GPP. The sidelink positioning service layer may be used for ranging between pairs of UEs and sidelink positioning for groups of UEs and may utilize the SLPP protocol (e.g., the SLPP protocol described elsewhere herein). Services provided by the sidelink positioning service layer to higher layers may include on-demand range / direction determination or relative location of another UE (one-time only), periodic range / direction determination or relative location of another UE, triggered range / direction determination or relative location of another UE (e.g., when range / direction or relative location changes by a threshold), on-demand range / direction determination or relative location for a group of other UEs (one-time only), periodic range / direction determination or relative location for a group of other UEs, and triggered range / direction determination or relative location for a group of other UEs (e.g., when range / direction or relative location changes by a threshold). Services requested by higher layers to the sidelink positioning service layer may include requests for the current range / direction or relative location of another UE (one-time, periodic or triggered) and requests for the current range / direction or relative location for a group UE (one-time, periodic or triggered). Services requested by the sidelink positioning service layer in the UE to the serving network (e.g., LMF) may include LMF support of sidelink positioning for PRS configuration determination or verification and location calculation, which may be an extension of the Mobile Originating-Location Request (MO-LR).

[0152] The roles of the UE upper layer and the external AF or client may also be defined. For example, the UE upper layer may request and receive information from the DSC, GS, and sidelink positioning service layers, determine group formation, positioning of other UEs, and provide services applicable to one or more applications (e.g., V2X, IIoT, etc.) using application level protocols. The external client or Application Function (AF) may receive information from the UE about other discovered UEs and groups of UEs, and may (i) request the current range / direction or relative location (one-time, periodic, or triggered) of two or more identified target UEs, (ii) request the current range / direction or relative location (one-time, periodic, or triggered) for a group of identified target UEs, and (iii) request the current range / direction or relative location of one identified target UE with other (unidentified) target UEs discovered by or in a group with this target UE. The request from an external client or AF may be sent to either the GMLC, which can forward the request to an LMF in the serving PLMN for the target UE, or to the Home SUPL SLP (H-SLP) for the target UE.

[0153] Figure 11 illustrates a schematic block diagram illustrating certain exemplary features of a UE 1100, which may be, for example, any of the UEs 105 illustrated in Figures 1, 3, 5, 6A, 6B, 6C, and 7, and the UEs illustrated in Figures 2, 8, 9, and 10, supporting sidelink positioning of the UE 1100 including group management as described herein. The UE 1100 may implement, for example, the signal flows 300, 500, 600, 620, 660, and 700 illustrated in Figures 3, 5, 6A, 6B, 6C, and 7, respectively, and the process flows 1300, 1400, 1500, 1600, and 1700 illustrated in Figures 13, 14, 15, 16, and 17, respectively, and associated techniques described herein. The UE 1100 may include, for example, one or more processors 1102, memory 1104, an external interface such as at least one wireless transceiver (e.g., wireless network interface) shown as a Wireless Wide Area Network (WWAN) transceiver 1110, a Wireless Local Area Network (WLAN) transceiver 1111, an Ultra Wide Band (UWB) transceiver 1112, and a Bluetooth (BT) transceiver 1113, an SPS receiver 1114, and one or more sensors 1115, which may be operatively coupled to a non-transitory computer-readable medium 1120 and memory 1104 using one or more connections 1106 (e.g., a bus, wires, fibers, links, etc.). The SPS receiver 1114 may receive and process SPS signals, for example, from a satellite vehicle 190 shown in FIG. The one or more sensors 1115 may be, for example, an Inertial Measurement Unit (IMU), which may include one or more accelerometers, one or more gyroscopes, magnetometers, etc. The UE 1100 may further include additional items not shown, such as a user interface through which a user may interface with the UE 1100, which may include a display, a keypad, or other input devices such as a virtual keypad on a display. In certain example implementations, all or a portion of the UE 1100 may be in the form of a chipset or the like.

[0154] The UE 1100 may include at least one wireless transceiver, such as a wireless transceiver 1110 for a WWAN communication system and a wireless transceiver 1111 for a WLAN communication system, a UWB transceiver 1112 for a UWB communication system, a BT transceiver 1113 for a Bluetooth communication system, or a combined transceiver for any of WWAN, WLAN, UWB, and BT. The WWAN transceiver 1110 may include a transmitter 1110t and a receiver 1110r coupled to one or more antennas 1109 to transmit (e.g., on one or more uplink channels and / or one or more sidelink channels) and / or receive (e.g., on one or more downlink channels and / or one or more sidelink channels) wireless signals and convert signals from wireless signals to wired (e.g., electrical and / or optical) signals and from wired (e.g., electrical and / or optical) signals to wireless signals. The WLAN transceiver 1111 may include a transmitter 1111t and a receiver 1111r coupled to one or more antennas 1109 or separate antennas to transmit (e.g., on one or more uplink channels and / or one or more sidelink channels) and / or receive (e.g., on one or more downlink channels and / or one or more sidelink channels) wireless signals and convert signals from wireless to wired (e.g., electrical and / or optical) signals and from wired (e.g., electrical and / or optical) signals to wireless signals. The UWB transceiver 1112 may include a transmitter 1112t and a receiver 1112r coupled to one or more antennas 1109 or separate antennas to transmit (e.g., on one or more uplink channels and / or one or more sidelink channels) and / or receive (e.g., on one or more downlink channels and / or one or more sidelink channels) wireless signals and convert signals from wireless to wired (e.g., electrical and / or optical) signals and from wired (e.g., electrical and / or optical) signals to wireless signals.The BT transceiver 1113 may include a transmitter 1113t and a receiver 1113r coupled to one or more antennas 1109 or separate antennas to transmit (e.g., on one or more uplink channels and / or one or more sidelink channels) and / or receive (e.g., on one or more downlink channels and / or one or more sidelink channels) wireless signals and convert signals from wireless signals to wired (e.g., electrical and / or optical) signals and from wired (e.g., electrical and / or optical) signals to wireless signals. The transmitters 1110t, 1111t, 1112t and 1113t may include multiple transmitters, which may be separate components or combined / integrated components, and / or the receivers 1110r, 1111r, 1112r and 1113r may include multiple receivers, which may be separate components or combined / integrated components. The WWAN transceiver 1110 may be configured to communicate signals (e.g., with base stations and / or one or more other UEs or other devices) in accordance with various radio access technologies (RATs), such as New Radio (NR), Global System for Mobiles (GSM), Universal Mobile Telecommunications System (UMTS), Advanced Mobile Phone System (AMPS), Code Division Multiple Access (CDMA), Wideband CDMA (WCDMA), Long-Term Evolution (LTE), LTE Direct (LTE-D), 3GPP LTE-V2X (PC5), etc. New Radio (NR) may use mmWave and / or sub-6 GHz frequencies.The WLAN transceiver 1111 may be configured to communicate signals (e.g., with an access point and / or one or more other devices) according to various radio access technologies (RATs), such as 3GPP LTE-V2X (PC5), IEEE 1102.11 (including IEEE 1102.11p), Wi-Fi, Wi-Fi Direct (Wi-Fi D), Zigbee, etc. The UWB transceiver 1112 may be configured to communicate signals (e.g., with an access point and / or one or more other devices) according to various radio access technologies (RATs), such as a personal area network (PAN), including IEEE 802.15.3, IEEE 802.15.4, etc. The BT transceiver 1113 may be configured to communicate signals (e.g., with an access point and / or one or more other devices) according to various radio access technologies (RATs), such as a Bluetooth network. The transceivers 1110, 1111, 1112, and 1113 may be communicatively coupled, for example by optical and / or electrical connections, to a transceiver interface that may be at least partially integrated with the transceivers 1110, 1111, 1112, and 1113.

[0155] In some embodiments, the UE 1100 may include an antenna 1109, which may be internal or external. The UE antenna 1109 may be used to transmit and / or receive signals that are processed by the wireless transceivers 1110, 1111, 1112, and 1113. In some embodiments, the UE antenna 1109 may be coupled to the wireless transceivers 1110, 1111, 1112, and 1113. In some embodiments, measurements of signals received (transmitted) by the UE 1100 may be performed at the connection point between the UE antenna 1109 and the wireless transceivers 1110, 1111, 1112, and 1113. For example, the measurement reference points of the received (transmitted) RF signal may be the input (output) UE of the receiver 1110r (transmitter 1110t) and the output (input) UE of the UE antenna 1109. In a UE 1100 having multiple UE antennas 1109, i.e. an antenna array, the antenna connector may be considered to be a virtual point representing the collective output (input) of the multiple UE antennas.

[0156] The one or more processors 1102 may be implemented using a combination of hardware, firmware, and software. For example, the one or more processors 1102 may be configured to perform functions described herein by implementing one or more instructions or program code 1108 on a non-transitory computer-readable medium, such as the medium 1120 and / or the memory 1104. In some embodiments, the one or more processors 1102 may represent one or more circuits configurable to execute at least a portion of a data signal computation procedure or process related to the operation of the UE 1100.

[0157] The medium 1120 and / or memory 1104 may store instructions or program code 1108, including executable code or software instructions that, when executed by the one or more processors 1102, cause the one or more processors 1102 to operate as a special purpose computer programmed to perform the techniques disclosed herein. As shown in the UE 1100, the medium 1120 and / or memory 1104 may include one or more components or modules that may be implemented by the one or more processors 1102 to perform the methods described herein. Although the components or modules are shown as software in the medium 1120 executable by the one or more processors 1102, it should be understood that the components or modules may be stored in the memory 1104 or may be dedicated hardware either within or external to the one or more processors 1102.

[0158] A number of software modules and data tables may reside in the medium 1120 and / or memory 1104 and be utilized by the one or more processors 1102 to manage both the communications and functionality described herein. It should be understood that the organization of the contents of the medium 1120 and / or memory 1104 as shown in the UE 1100 is merely exemplary, and that the functionality of the modules and / or data structures may be combined, separated, and / or structured in various ways depending on the implementation of the UE 1100.

[0159] The medium 1120 and / or the memory 1104 may include a SLPP message module 1122 that, when implemented by the one or more processors 1102, configures the one or more processors 1102 to send and receive sidelink positioning (e.g., SLPP) messages over an external interface including one or more of the wireless transceivers 1110, 1111, 1112, and 1113. The sidelink positioning messages may use SLPP as described herein. The one or more processors 1102 may be configured to send the SLPP messages directly to one or more other UEs or to broadcast the SLPP messages to multiple other UEs using groupcast or multicast over the external interface. The one or more processors 1102 may be configured to transmit and receive SLPP messages with a location server (e.g., LMF) in the PLMN using SLPP messages embedded in LPP messages, embedded in both LPP messages and SUPL messages (e.g., which may include SUPL POS messages), embedded only in SUPL messages (e.g., which may include SUPL POS messages), or not embedded in LPP messages or SUPL messages via the external interface. The one or more processors 1102 may be configured to transmit and receive SLPP messages including, for example, an SLPP capability request or SLPP capabilities, SLPP resources, and / or SLPP service requirements for the UE via the external interface. The one or more processors 1102 may be configured to transmit and receive, for example, a proposed PRS configuration for sidelink positioning via the external interface, and may be configured to transmit and receive a confirmation, rejection, or modification of a proposed PRS configuration for sidelink positioning via the external interface. The sidelink positioning messages may use SLPP as described herein. The one or more processors 1102 may be configured to send or receive SLPP messages including measurement reports or location results, for example, via an external interface.The transmitted measurement report may include, for example, information on sidelink positioning signals transmitted by the UE and measurements performed by the UE 1100 on sidelink positioning signals transmitted by other UEs, and may include an indication of reverse link communication from each UE in the group to the UE 1100. The received measurement report may include measurements performed by other UEs, including, for example, measurements on sidelink positioning signals transmitted by the UE 1100, and may include an indication of reverse link communication from each UE in the group to each of the other UEs in the group. The location results may include range, distance, and / or direction between one or more pairs of UEs in the group, and / or relative locations, absolute locations, and / or velocities and / or relative speeds for each of the one or more UEs in the group.

[0160] The medium 1120 and / or the memory 1104 may include a PRS module 1123 that, when implemented by the one or more processors 1102, configures the one or more processors 1102 to transmit a PRS for sidelink positioning (e.g., a sidelink PRS or a sidelink SRS for NR or LTE) via an external interface including one or more of the wireless transceivers 1110, 1111, 1112, and 1113. The one or more processors 1102 may be configured to transmit a SL PRS that matches a proposed SL PRS configuration sent to or received from another UE. The one or more processors 1102 may be further configured to receive a SL PRS from the other UE via the external interface and measure the SL PRS for sidelink positioning.

[0161] The medium 1120 and / or the memory 1104 may include a location module 1124 that, when implemented by the one or more processors 1102, configures the one or more processors 1102 to determine a location result for one or more UEs relative to the UE 1100 based on the SL PRS measurements performed by the UE 1100 and measurement information received in SLPP messages from the other UEs. The one or more processors 1102 may be further configured to determine a velocity of the UE 1100 and / or the other UEs based on the SL PRS measurements performed by the UE 1100 and measurement information received in SLPP messages from the other UEs.

[0162] The medium 1120 and / or the memory 1104 may include a discovery module 1126 that, when implemented by the one or more processors 1102, configures the one or more processors 1102 to discover one or more other UEs that are available for sidelink positioning. The one or more processors 1102 may be further configured to obtain group criteria parameters for the other UEs, such as a distance restriction, a time restriction, a movement direction restriction, a speed restriction, a sidelink positioning method restriction, or a sidelink positioning method type restriction.

[0163] The medium 1120 and / or memory 1104 may include a group management module 1128 that, when implemented by the one or more processors 1102, configures the one or more processors 1102 to determine a group status indication for one or more UEs indicating the inclusion or exclusion of a UE in the group based on the group criteria parameters. The one or more processors 1102 may be further configured to determine a group status indication for one or more UEs in the group indicating the inclusion or exclusion of a UE in the group based on an indication of reverse link communication for the one or more UEs, including an indication of reverse link communication from each UE and an indication of reverse link communication from the UE 1100. The one or more processors 1102 may be further configured to determine a status of forward link communication and a status of reverse link communication between all pairs of UEs in the group based on the indication of reverse link communication from each UE in the group. The one or more processors 1102 may be further configured to determine a group status indication for the one or more UEs based on a status of forward link communication and a status of reverse link communication between all pairs of UEs in the group. The one or more processors 1102 may be further configured to cause an addition or transfer of one or more UEs from one group to another group based on a relative location and velocity of the one or more UEs and the UEs in the group.

[0164] The methods described herein may be implemented by various means depending on the application. For example, the methods may be implemented in hardware, firmware, software, or any combination thereof. In the case of a hardware implementation, the one or more processors 1102 may be implemented with one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, electronic devices, other electronic units designed to perform the functions described herein, or combinations thereof.

[0165] For firmware and / or software implementations, the methods may be implemented with modules (e.g., procedures, functions, etc.) that perform the functions described herein. Any machine-readable medium tangibly embodying instructions may be used in performing the methods described herein. For example, software code may be stored in a non-transitory computer-readable medium 1120 or memory 1104 coupled to and executed by one or more processors 1102. The memory may be implemented within the one or more processors or external to the one or more processors. The term "memory" as used herein refers to any type of long-term memory, short-term memory, volatile memory, non-volatile memory, or other memory, and is not limited to a particular type or number of memories, or to a particular type of medium on which the memory is stored.

[0166] If implemented in firmware and / or software, the functions may be stored as one or more instructions or program code 1108 on a non-transitory computer readable medium, such as the medium 1120 and / or the memory 1104. Examples include computer readable media encoded with data structures and computer readable media encoded with computer program code 1108. For example, the non-transitory computer readable medium on which the program code 1108 is stored may include the program code 1108 for supporting sidelink positioning in a manner consistent with the disclosed embodiments. The non-transitory computer readable medium 1120 includes physical computer storage media. The storage media may be any available medium that can be accessed by a computer. By way of example and not limitation, such non-transitory computer readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired program code 1108 in the form of instructions or data structures and that can be accessed by a computer. As used herein, "disk" and "disc" include a compact disc (CD), a laser disc, an optical disc, a digital versatile disc (DVD), a floppy disk, and a Blu-ray disc, although a "disk" typically reproduces data magnetically and a "disc" reproduces data optically using a laser. Combinations of the above are also intended to be included within the scope of computer-readable media.

[0167] In addition to being stored on the computer-readable medium 1120, the instructions and / or data may be provided as signals on a transmission medium contained within the communications device. For example, the communications device may include an external interface including one or more of wireless transceivers 1110, 1111, 1112, and 1113 having signals indicative of the instructions and data. The instructions and data are configured to cause one or more processors to perform the functions outlined in the claims. That is, the communications device includes a transmission medium having signals indicative of information to perform the disclosed functions.

[0168] Memory 1104 may represent any data storage mechanism. Memory 1104 may include, for example, primary memory and / or secondary memory. Primary memory may include, for example, random access memory, read-only memory, etc. Although shown in this example as being separate from one or more processors 1102, it should be understood that all or a portion of the primary memory may be provided within one or more processors 1102 or may otherwise be co-located / coupled with one or more processors 1102. Secondary memory may include, for example, the same or similar type of memory as the primary memory and / or one or more data storage devices or systems, such as, for example, disk drives, optical disk drives, tape drives, solid state memory drives, etc.

[0169] In certain implementations, the secondary memory may operably receive or be otherwise configurable to couple to a non-transitory computer-readable medium 1120. Thus, in certain example implementations, the methods and / or apparatuses presented herein may take the form, in whole or in part, of a computer-readable medium 1120 having stored thereon computer-implementable program code 1108 that, when executed by one or more processors 1102, may be operably enabled to perform all or a portion of the example operations as described herein. The computer-readable medium 1120 may be part of the memory 1104.

[0170] Figure 12 shows a schematic block diagram illustrating certain exemplary features of a location server 1200, which may be the LMF 120, SUPL SLP 119, or server 121 or 123 shown in Figure 1A, or the LMF 120a or 120b, SUPL SLP 119a or 119b, or server 121a, 121b, or 123 shown in Figure 2, or the location server 302 shown in Figure 3, supporting sidelink positioning supported by the network as described herein. The location server 1200 may be, for example, an LMF or a SUPL SLP (Secure User Plane Location (SUPL) Location Platform). The location server 1200 may implement, for example, the signal flow 300 shown in Figure 3 and the accompanying techniques described herein. The location server 1200 may include, for example, one or more processors 1202 and memory 1204, an external interface 1210, which may be operatively coupled to the non-transitory computer-readable medium 1220 and the memory 1204 using one or more connections 1206 (e.g., buses, wiring, fibers, links, etc.). The external interface 1210 may be a wired and / or wireless interface capable of connecting to a network entity in the core network 140, such as an AMF or UPF, through which the location server 1200 may communicate with RAN nodes and UEs. The location server 1200 may further include additional items not shown, such as, for example, a user interface, which may include a display, a keypad such as a virtual keypad on the display, or other input device through which a user may interface with the location server. In certain example implementations, all or a portion of the location server 1200 may take the form of a chipset or the like.

[0171] The one or more processors 1202 may be implemented using a combination of hardware, firmware, and software. For example, the one or more processors 1202 may be configured to perform functions described herein by implementing one or more instructions or program code 1208 on a non-transitory computer-readable medium, such as the medium 1220 and / or the memory 1204. In some embodiments, the one or more processors 1202 may represent one or more circuits that can be configured to perform at least a portion of a data signal calculation procedure or process related to the operation of the location server 1200.

[0172] The medium 1220 and / or memory 1204 may store instructions or program code 1208, including executable code or software instructions that, when executed by the one or more processors 1202, cause the one or more processors 1202 to operate as a special purpose computer programmed to perform the techniques disclosed herein. As shown in the location server 1200, the medium 1220 and / or memory 1204 may include one or more components or modules that may be implemented by the one or more processors 1202 to perform the methods described herein. Although the components or modules are shown as software in the medium 1220 executable by the one or more processors 1202, it should be understood that the components or modules may be stored in the memory 1204 or may be dedicated hardware either within or external to the one or more processors 1202.

[0173] A number of software modules and data tables may reside in the medium 1220 and / or memory 1204 and be utilized by the one or more processors 1202 to manage both the communications and functionality described herein. It should be understood that the organization of the contents of the medium 1220 and / or memory 1204 as shown in the location server 1200 is only an example, and thus the functionality of the modules and / or data structures may be combined, separated, and / or structured differently depending on the implementation of the location server 1200.

[0174] The medium 1220 and / or memory 1204 may include a SLPP message module 1222 that, when implemented by the one or more processors 1202, configures the one or more processors 1202 to transmit and receive SLPP messages with the UE via the external interface 1210. The sidelink positioning messages may use SLPP as described herein. The one or more processors 1202 may be configured to transmit and receive SLPP messages that are not embedded in LPP messages, embedded in LPP messages, embedded in SUPL messages (which may include SUPL POS messages), or embedded in both LPP and SUPL messages (which may include SUPL POS messages), via the external interface 1210. The one or more processors 1202 may be configured to transmit and receive SLPP messages that include, for example, an SLPP capability request or SLPP capabilities, SLPP resources, and / or SLPP service requirements for the UE via the external interface 1210. The one or more processors 1202 may be configured to transmit and receive, e.g., via the external interface 1210, a proposed SL PRS configuration for sidelink positioning, and may be configured to transmit and receive, e.g., via the external interface 1210, a confirmation, rejection, or modification of a proposed SL PRS configuration for sidelink positioning. The one or more processors 1202 may be configured to transmit and receive, e.g., via the external interface 1210, a SLPP message including a measurement report or a location result. The measurement report may include measurements performed by the UE, including, e.g., measurements on sidelink positioning signals transmitted by the UE, and may include an indication of reverse link communications from each UE in the group to each other UE in the group. The location result may include range, distance, and / or direction between one or more pairs of UEs in the group, and / or a relative location, absolute location, and / or velocity for each of the one or more UEs in the group.

[0175] The medium 1220 and / or the memory 1204 may include an SL PRS configuration module 1223 that, when implemented by the one or more processors 1202, configures the one or more processors 1202 to generate or verify a configuration of an SL PRS to be transmitted by one or more UEs for sidelink positioning. The one or more processors 1202 may be configured to, for example, obtain SLPP capabilities, SLPP resources, and SLPP service requirements for one or more UEs. The one or more processors 1202 may be configured to obtain the SL PRS configuration for the UE.

[0176] The medium 1220 and / or memory 1204 may include a location module 1224 that, when implemented by the one or more processors 1202, configures the one or more processors 1202 to determine a location result for one or more UEs based on the SL PRS measurements performed by the UE. The one or more processors 1202 may be further configured to determine a velocity of the UE based on the SL PRS measurements performed by the UE. The one or more processors 1202 may be further configured to send the location result, such as a range, a direction, a relative location and / or a velocity for the UE, to the UE via the external interface 1210.

[0177] The methods described herein may be implemented by various means depending on the application. For example, the methods may be implemented in hardware, firmware, software, or any combination thereof. In the case of a hardware implementation, the one or more processors 1202 may be implemented with one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, electronic devices, other electronic units designed to perform the functions described herein, or combinations thereof.

[0178] For firmware and / or software implementations, the methods may be implemented with modules (e.g., procedures, functions, etc.) that perform the functions described herein. Any machine-readable medium tangibly embodying instructions may be used in implementing the methods described herein. For example, software code may be stored in non-transitory computer-readable medium 1220 or memory 1204 coupled to and executed by one or more processors 1202. Memory may be implemented within one or more processors or external to one or more processors. The term "memory" as used herein refers to any type of long-term memory, short-term memory, volatile memory, non-volatile memory, or other memory, and is not limited to a particular type or number of memories, or to a particular type of medium on which the memory is stored.

[0179] If implemented in firmware and / or software, the functions may be stored as one or more instructions or program code 1208 on a non-transitory computer readable medium, such as the medium 1220 and / or the memory 1204. Examples include computer readable media encoded with data structures and computer readable media encoded with computer program code 1208. For example, the non-transitory computer readable medium on which the program code 1208 is stored may include program code 1208 for enabling network supported sidelink positioning in a manner consistent with the disclosed embodiments. The non-transitory computer readable medium 1220 includes physical computer storage media. The storage media may be any available medium that can be accessed by a computer. By way of example and not limitation, such non-transitory computer readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired program code 1208 in the form of instructions or data structures and that can be accessed by a computer. As used herein, "disk" and "disc" include compact discs (CDs), laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and Blu-ray discs, although a "disk" typically reproduces data magnetically and a "disc" reproduces data optically using a laser. Combinations of the above are also intended to be included within the scope of computer-readable media.

[0180] In addition to being stored on the computer-readable medium 1220, the instructions and / or data may be provided as signals on a transmission medium contained within the communications device. For example, the communications device may include an external interface 1210 having signals indicative of instructions and data. The instructions and data are configured to cause one or more processors to perform the functions outlined in the claims. That is, the communications device includes a transmission medium having signals indicative of information to perform the disclosed functions.

[0181] Memory 1204 may represent any data storage mechanism. Memory 1204 may include, for example, primary memory and / or secondary memory. Primary memory may include, for example, random access memory, read-only memory, etc. Although shown in this example as being separate from one or more processors 1202, it should be understood that all or a portion of the primary memory may be provided within one or more processors 1202 or may otherwise be co-located / coupled with one or more processors 1102. Secondary memory may include, for example, the same or similar type of memory as the primary memory, and / or one or more data storage devices or systems, such as, for example, disk drives, optical disk drives, tape drives, solid state memory drives, etc.

[0182] In certain implementations, the secondary memory may operably receive or be otherwise configurable to couple to a non-transitory computer-readable medium 1220. Thus, in certain example implementations, the methods and / or apparatuses presented herein may take the form, in whole or in part, of a computer-readable medium 1220 having stored thereon computer-implementable program code 1208 that, when executed by one or more processors 1202, may be operably enabled to perform all or a portion of the example operations as described herein. The computer-readable medium 1220 may be part of the memory 1204.

[0183] FIG. 13 illustrates a flowchart for an example method 1300 for supporting sidelink (SL) positioning of a UE and multiple other UEs (e.g., other UEs 105 or other UEs 1100) performed by a UE, such as UE 105 or UE 1100, as described herein, in a manner consistent with the disclosed implementations.

[0184] In block 1302, the UE sends a first SLPP message to all of the multiple other UEs, e.g., as shown in step 1 of Figures 5 and 7 and step 1 of Figure 6A. In one implementation, the first SLPP message may include the UE's SLPP capabilities and SLPP resources, e.g., as described in step 1 of Figures 5 and 7 and step 1 of Figure 6A. The means for sending the first SLPP message to all of the multiple other UEs may include, e.g., one of the transceivers 1110-1113 and one or more processors 1102 having dedicated hardware or implementing executable code or software instructions in memory 1104 and / or medium 1120, such as an SLPP message module 1122 of the UE 1100.

[0185] At block 1304, the UE receives a second SLPP message from each UE of the plurality of other UEs, the second SLPP message received from each UE including the SLPP capabilities of each UE and the SLPP resources of each UE, e.g., as shown in step 1 of Figures 5 and 7 and step 2 of Figure 6A. The means for receiving a second SLPP message from each UE of the plurality of other UEs, the second SLPP message received from each UE including the SLPP capabilities of each UE and the SLPP resources of each UE, may include, for example, one of the transceivers 1110-1113 and one or more processors 1102 having dedicated hardware or implementing executable code or software instructions in memory 1104 and / or medium 1120, such as SLPP message module 1122 of UE 1100.

[0186] In block 1306, the UE exchanges additional SLPP messages with at least some of the multiple other UEs, where the additional SLPP messages are based on the SLPP capabilities and SLPP resources of each of the at least some of the UEs, e.g., as shown in steps 2-6 of Figure 5, steps 2-8 of Figure 7, and signal flows 620 and 660 of Figures 6B and 6C. Means for exchanging additional SLPP messages with at least some of the multiple other UEs, where the additional SLPP messages are based on the SLPP capabilities and SLPP resources of each of the at least some of the UEs, may include, for example, one of the transceivers 1110-1113 and one or more processors 1102 having dedicated hardware or implementing executable code or software instructions in memory 1104 and / or medium 1120, such as SLPP message module 1122 of UE 1100.

[0187] In block 1308, the UE determines location results for at least some of the UEs based on the additional SLPP messages, e.g., as shown in step 7 of FIG. 5 and step 9 of FIG. 7. The location results may include at least one of a range between the pair of UEs, a direction from the UE to another UE, a location of the UE relative to a location of the other UE, a velocity of the UE, a relative velocity of the UE relative to another UE, or some combination thereof. The relative velocity of UE B relative to another UE A may include a "radial velocity" component that may be equal to a rate of change of range from UE A to UE B, and a "lateral velocity" component that may be orthogonal to the radial velocity component (e.g., from the perspective of UE A) and may be equal to an angular rate of change of the direction from UE A to UE B multiplied by the range from UE A to UE B. The means for determining location results for at least some of the UEs based on the additional SLPP messages may include, for example, one or more processors 1102 having dedicated hardware or implementing executable code or software instructions in memory 1104 and / or medium 1120, such as a location module 1124 of the UE 1100.

[0188] In one implementation, the UE may send a first SLPP message to all UEs of the plurality of other UEs, receive a second SLPP message from each UE of the plurality of other UEs, and exchange additional SLPP messages with at least some of the plurality of other UEs based on SL multicast, for example, when the plurality of other UEs includes two or more UEs, as described with respect to signal flow 700 shown in FIG. 7 .

[0189] In one implementation, the UE's SLPP resources may provide an indication of the SLPP capabilities that the UE is authorized to support, the SLPP capabilities that the UE is not authorized to support, or both, as described, for example, with reference to signal flows 500 and 700 shown in FIGS. 5 and 7. For example, the SLPP capabilities that a UE is permitted or not permitted to support may include at least one of: permission or restriction on SL positioning reference signal (PRS) transmission time, permission or restriction on SL PRS measurement time, permission or restriction on SL PRS transmission duration, permission or restriction on SL PRS measurement duration, permission or restriction on bandwidth of SL PRS transmission, permission or restriction on bandwidth of the SL PRS being measured, permission or restriction on RF frequency of SL PRS transmission, permission or restriction on RF frequency of the SL PRS being measured, permission or restriction on signal coding of SL PRS transmission, permission or restriction on signal coding of the SL PRS being measured, permission or restriction on periodicity of SL PRS transmission, permission or restriction on periodicity of SL PRS measurement, permission or restriction on transmit power for SL PRS transmission, permission or restriction on transmit power for the SL PRS being measured, and any combination thereof, for example, as described with reference to signal flows 500 and 700 shown in FIGS. 5 and 7.

[0190] In one implementation, the second SLPP message received from each UE may further include the SLPP service requirements of each UE, and the additional SLPP message is further based on the SLPP service requirements of each UE in at least some of the UEs, e.g., as described in steps 1-6 of Figure 5, steps 1-8 of Figure 7, step 2 of Figure 6A, and signal flows 620 and 660 of Figures 6B and 6C. In one implementation, the first SLPP message may further include the SLPP service requirements of the UE, e.g., as described in step 1 of Figures 5 and 7, and step 1 of Figure 6A. The SLPP service requirements of the UE may include at least one indication of an immediate location, a deferred location, a periodic location, a triggered location, a relative location, a global location, a location accuracy, a location latency, a location periodicity, a location reliability, or any combination thereof, e.g., as described in step 1 of Figures 5 and 7, and step 1 of Figure 6A.

[0191] FIG. 14 shows a flowchart of an example method 1400 for determining a group of UEs for performing sidelink (SL) positioning, performed by a UE, such as UE 105 or UE 1100 described herein, in a manner consistent with the disclosed implementations.

[0192] In block 1402, the UE discovers a plurality of UEs (e.g., other UEs 105 or UE 1100) available for SL positioning, including the UE, as described, for example, with reference to Figures 5 and stage 0 of Figure 7 and Figure 8. Means for discovering a plurality of UEs available for sidelink positioning, including the UE, may include, for example, one of the transceivers 1110-1113 and one or more processors 1102 having dedicated hardware or implementing executable code or software instructions in memory 1104 and / or medium 1120, such as a discovery module 1126 of the UE 1100.

[0193] In block 1404, the UE determines one or more group criteria parameters (e.g., using preconfigured information in the UE or by obtaining group criteria parameters from each of the plurality of UEs), e.g., as described with reference to stage 0 of FIG. 5 and FIG. 7 and FIG. 8. In one implementation, the one or more group criteria parameters may include at least one of a distance restriction, a time restriction, a moving direction restriction, or a speed restriction, e.g., as described with reference to FIG. 8. In one implementation, the one or more group criteria parameters may include at least one of a SL positioning method restriction or a SL positioning method type restriction, e.g., as described with reference to FIG. 8. The means for obtaining the one or more group criteria parameters from each of the plurality of UEs may include, for example, one of the transceivers 1110-1113 and one or more processors 1102 having dedicated hardware or implementing executable code or software instructions in the memory 1104 and / or the medium 1120, such as the discovery module 1126 of the UE 1100.

[0194] In block 1406, the UE determines a group status indication for at least one UE in the plurality of UEs based on one or more group criteria parameters, the group status indication for the at least one UE indicating inclusion or exclusion of the at least one UE in the group, e.g., as described with reference to stage 0 of Figures 5 and 7 and Figure 8. The means for determining a group status indication for at least one UE in the plurality of UEs based on one or more group criteria parameters, the group status indication for the at least one UE indicating inclusion or exclusion of the at least one UE in the group, may include one or more processors 1102 having dedicated hardware or implementing executable code or software instructions in memory 1104 and / or medium 1120, such as group management module 1128 of UE 1100, for example.

[0195] In one implementation, for example, as described with reference to FIG. 8, at least one UE may be included in a group when a group status indication for the at least one UE indicates including the at least one UE in the group, and at least one UE may be excluded from a group when a group status indication for the at least one UE indicates excluding the at least one UE from the group.

[0196] In one implementation, for example, as described with reference to FIG. 8, each of the other UEs in the plurality of UEs may determine a group status indication for the at least one UE based on group criteria parameters obtained from the UE or from other UEs in the plurality of UEs, and the at least one UE is included in or excluded from the group based on the group status indication for the at least one UE determined by each of the UEs in the plurality of UEs.

[0197] FIG. 15 shows a flowchart of an example method 1500 for enabling a group of UEs (e.g., other UEs 105 or 1100) to perform sidelink (SL) positioning, performed by a UE, such as, for example, UE 105 or UE 1100 described herein, in a manner consistent with the disclosed implementations.

[0198] In block 1502, the UE sends to each of the other UEs in the group an indication of reverse link communications from each UE in the group to the UE, e.g., as described with reference to step 8 of Figure 7 and Figures 8 and 9. Means for sending to each of the other UEs in the group an indication of reverse link communications from each UE in the group to the UE may include, for example, one of the transceivers 1110-1113 and one or more processors 1102 having dedicated hardware or implementing executable code or software instructions in memory 1104 and / or medium 1120, such as SLPP message module 1122 of UE 1100.

[0199] In block 1504, the UE receives an indication of reverse link communications from each of the other UEs in the group to each of the other UEs, e.g., as described with reference to step 8 of Figure 7 and Figures 8 and 9. Means for receiving an indication of reverse link communications from each of the other UEs in the group to each of the other UEs may include, for example, one of the transceivers 1110-1113 and one or more processors 1102 having dedicated hardware or implementing executable code or software instructions in memory 1104 and / or medium 1120, such as an SLPP message module 1122 of the UE 1100.

[0200] In block 1506, the UE determines a group status indication for at least one UE in the group based on the indication of reverse link communication from each UE in the group to the UE and the indication of reverse link communication from each UE in the group to each other UE in the group, the group status indication for the at least one UE indicating inclusion or exclusion of the at least one UE from the group, as described with reference to Figures 8 and 9, for example. The means for determining a group status indication for at least one UE in the group based on the indication of reverse link communication from each UE in the group to the UE and the indication of reverse link communication from each UE in the group to each other UE in the group, the group status indication for the at least one UE indicating inclusion or exclusion of the at least one UE from the group, may include one or more processors 1102 having dedicated hardware or implementing executable code or software instructions in memory 1104 and / or medium 1120, such as group management module 1128 of UE 1100, for example.

[0201] In one implementation, for example, as described with respect to signal flow 700 shown in FIG. 7, a UE may send an indication of reverse link communication to, and receive an indication of reverse link communication from, each of the other UEs in the group based on SL multicast when the group includes three or more UEs.

[0202] In one implementation, the indication of reverse link communication from any UE in the group to any other UE in the group indicates whether SLPP signaling transmitted by any UE was or was not received by any other UE, e.g., as described with reference to Figure 9. The SLPP signaling may include, e.g., SLPP messages, SL Positioning Reference Signals (PRS), or both, e.g., as described with reference to steps 4-8 of Figure 7 and Figures 8 and 9.

[0203] In one implementation, for example, as described with reference to Figures 8 and 9, at least one UE may be included in a group when a group status indication of the at least one UE indicates to include the at least one UE in the group, and at least one UE may be excluded from a group when a group status indication of the at least one UE indicates to exclude the at least one UE from the group.

[0204] In one implementation, for example, as described with reference to Figures 8 and 9, each of the other UEs in the group may determine a group status indication for the at least one UE based on an indication of reverse link communications received from the other UEs in the group, and the at least one UE may be included in or excluded from the group based on the group status indication for the at least one UE determined by each of the UEs in the group.

[0205] In one implementation, the UE may further determine a status of forward link communication and a status of reverse link communication between all pairs of UEs in the group based on an indication of reverse link communication from each UE in the group to the UE and an indication of reverse link communication from each UE in the group to each other UE in the group. For example, as described with reference to FIG. 9, the status of forward link communication and the status of reverse link communication between any pair of UEs in the group may indicate whether successful SLPP signaling transfer between the pair of UEs is currently possible, is currently not possible, or has an unknown status, for each of the forward and reverse transfer directions, respectively. For example, as described with reference to FIG. 9, the UE may determine a group status indication for at least one UE based on the status of forward link communication and the status of reverse link communication between all pairs of UEs in the group. Means for determining a status of forward link communication and a status of reverse link communication between all pairs of UEs in the group based on an indication of reverse link communication from each UE in the group to the UE and an indication of reverse link communication from each UE in the group to each other UE in the group may include, for example, one or more processors 1102 having dedicated hardware or implementing executable code or software instructions in memory 1104 and / or medium 1120, such as a group management module 1128 of the UE 1100. Means for determining a group status indication for at least one UE based on a status of forward link communication and a status of reverse link communication between all pairs of UEs in the group may include, for example, one or more processors 1102 having dedicated hardware or implementing executable code or software instructions in memory 1104 and / or medium 1120, such as a group management module 1128 of the UE 1100.

[0206] In one implementation, the indication of reverse link communication is an implicit indication, where reverse link communication from UE B to another UE A is assumed to exist when UE A reports one or more measurements obtained by UE A for a sidelink PRS transmitted by UE B, and reverse link communication from UE B to UE A is assumed not to exist when UE A does not report any measurements obtained by UE A for a sidelink PRS transmitted by UE B or when UE A provides an indication that it was not able to obtain any measurements for a SL PRS transmitted by UE B.

[0207] FIG. 16 shows a flowchart of an example method 1600 for enabling a first group of UEs including the UE (e.g., other UEs 105 or 1100) and a second group of UEs including the UE (e.g., further UEs 105 or 1100) to perform sidelink (SL) positioning, performed by a UE, such as, for example, the UE 105 or UE 1100 described herein, in a manner consistent with the disclosed implementations.

[0208] In block 1602, the UE obtains location results for a first set of UEs in the first group that do not belong to the second group, e.g., as described with reference to steps 9 and 10 of Figure 7 and Figure 10. The means for obtaining location results for the first set of UEs in the first group that do not belong to the second group may have dedicated hardware or include one or more processors 1102 implementing executable code or software instructions in memory 1104 and / or medium 1120, such as location module 1124 of UE 1100, for example.

[0209] In block 1604, the UE obtains location results for a second set of UEs in the second group that do not belong to the first group, e.g., as described with reference to steps 9 and 10 of Figure 7 and Figure 10. Means for obtaining location results for a second set of UEs in the second group that do not belong to the first group may have dedicated hardware or include one or more processors 1102 implementing executable code or software instructions in memory 1104 and / or medium 1120, such as location module 1124 of UE 1100, for example.

[0210] The location results for the first set of UEs in the first group and the location results for the second set of UEs in the second group each include at least one of a range between the pair of UEs, a direction from the UE to another UE, a location of the UE relative to a location of the other UE, a velocity of the UE, a relative velocity of the UE with respect to another UE, or any combination thereof.

[0211] In block 1606, the UE causes at least one of adding or transferring at least some of the first set of UEs to the second group and adding or transferring at least some of the second set of UEs to the first group based on the location results for the first set of UEs and the second set of UEs, as described with reference to FIG. 10. In one implementation, the adding or transferring at least some of the first set of UEs or at least some of the second set of UEs merges the first group with the second group, for example, as described with reference to FIG. 10. Means for causing one of adding or transferring at least some of the first set of UEs to the second group and adding or transferring at least some of the second set of UEs to the first group based on the location results for the first set of UEs and the second set of UEs may include one or more processors 1102 having dedicated hardware or implementing executable code or software instructions in memory 1104 and / or medium 1120, such as group management module 1128 of UE 1100, for example.

[0212] FIG. 17 shows a flowchart of an example method 1700 for supporting sidelink (SL) positioning for a group of UEs including the UE (e.g., other UEs 105 or 1100) performed by a UE, such as, for example, UE 105 or UE 1100 described herein, in a manner consistent with the disclosed implementations.

[0213] At block 1702, the UE receives a first SLPP message from a first UE in the group, e.g., as described with reference to Figures 2, 310 of Figure 3, and 4. The means for receiving the first SLPP message from the first UE in the group may include, for example, one of the transceivers 1110-1113 and one or more processors 1102 having dedicated hardware or implementing executable code or software instructions in memory 1104 and / or medium 1120, such as an SLPP message module 1122 of the UE 1100.

[0214] At block 1704, the UE sends a first SLPP message to a location server in a public land mobile network (PLMN), e.g., as described with reference to Figures 2, 320 of Figure 3, and Figure 4. Means for sending a first SLPP message to a location server in a public land mobile network (PLMN) may include, for example, one of the transceivers 1110-1113 and one or more processors 1102 having dedicated hardware or implementing executable code or software instructions in memory 1104 and / or medium 1120, such as an SLPP message module 1122 of the UE 1100.

[0215] At block 1706, the UE receives a second SLPP message from the location server in response to the first SLPP message, e.g., as described with reference to Figures 2, 330 of Figure 3, and 4. Means for receiving a second SLPP message from the location server in response to the first SLPP message may include, for example, one of the transceivers 1110-1113 and one or more processors 1102 having dedicated hardware or implementing executable code or software instructions in memory 1104 and / or medium 1120, such as an SLPP message module 1122 of the UE 1100.

[0216] At block 1708, the UE sends a second SLPP message to other UEs in the group, e.g., as described with reference to Figures 2, 340 of Figure 3, and 4. Means for sending the second SLPP message to other UEs in the group may include, for example, one of the transceivers 1110-1113 and one or more processors 1102 having dedicated hardware or implementing executable code or software instructions in memory 1104 and / or medium 1120, such as an SLPP message module 1122 of the UE 1100.

[0217] In one implementation, sending a first SLPP message to the location server may include sending a first LPP message to the location server, the first LPP message including the first SLPP message, as described, for example, with respect to 320 of Figure 3. Receiving a second SLPP message from the location server may further include receiving a second LPP message from the location server, the second LPP message including the second SLPP message, as described, for example, with respect to 330 of Figure 3.

[0218] In one implementation, for example, as described with reference to FIG. 3, a UE may receive a first SLPP message from a first UE in the group and send a second SLPP message to other UEs in the group based on SL multicast when the group of UEs includes three or more UEs.

[0219] In one implementation, the second SLPP message may include location results for one or more UEs in the group, for example, as described with respect to 330 in Figure 3. The location results for one or more UEs in the group may include at least one of a range between a pair of UEs, a direction from the UE to another UE, a location of the UE relative to a location of the other UE, a velocity of the UE, a relative velocity of the UE with respect to another UE, or some combination thereof, for example, as described with respect to 330 in Figure 3.

[0220] In one implementation, the first SLPP message may include SLPP capabilities, SLPP resources, or both for at least one other UE in the group, e.g., as described with reference to Figures 2 and 310 and 320 of Figure 3. For example, the first SLPP message may be a SLPP capability provision message, e.g., as described with reference to Figures 2 and 310 and 320 of Figure 3.

[0221] In one implementation, the second SLPP message may include SLPP capabilities, SLPP resources, or both for the UE, for example, as described with reference to Figures 2 and 330 and 340 of Figure 3. For example, the second SLPP message may be an SLPP capability provision, as described with reference to Figures 2 and 330 of Figure 3.

[0222] In one implementation, the first SLPP message may include a SL Positioning Reference Signal (PRS) configuration for at least one UE in the group, e.g., as described with reference to Figures 2 and 310 and 320. The first SLPP message may be a SLPP Request Assistance Data message or a SLPP Provide Assistance Data message, e.g., as described with reference to Figures 2 and 320.

[0223] In one implementation, the second SLPP message may include a SL Positioning Reference Signal (PRS) configuration for at least one UE in the group, e.g., as described with reference to 330 and 340 in Figures 2 and 3. The second SLPP message may include a Provide SLPP Assistance Data message, e.g., as described with reference to 330 in Figures 2 and 3.

[0224] In one implementation, the first SLPP message may include SLPP measurements obtained by at least one UE in the group, e.g., as described with reference to Figures 2 and 310 and 320 of Figure 3. For example, the first SLPP message may include a SLPP location information request message or a SLPP location information provide message, as described with reference to Figures 2 and 320 of Figure 3.

[0225] In one implementation, for example, as described with reference to Figures 2 and steps 330 and 340 of Figure 3, the second SLPP message may include location results for one or more UEs in the group, and the second SLPP message may include a SLPP location information provision message.

[0226] In one implementation, the location server may be a location management function (e.g., LMF 120) or a secure user plane location (SUPL) location platform (e.g., SLP 119), e.g., as described with reference to Figures 2 and 3. For example, as described with reference to Figures 2 and 320 and 330 of Figure 3, the location server may be, e.g., a SUPL SLP, and the first SLPP message may be sent to the location server as part of a first SUPL message and the second SLPP message may be received from the location server as part of a second SUPL message. As described with reference to Figure 3, the first SUPL message and the second SUPL message may each include a SUPL POS message.

[0227] Substantial variations may be made according to particular needs. For example, customized hardware may be used and / or particular elements may be implemented in hardware, software (including portable software such as applets), or both. Furthermore, connection to other computing devices, such as network input / output devices, may be utilized.

[0228] The configurations may be described as processes that are shown as flow charts or block diagrams. Although the flow charts or block diagrams may describe operations as sequential processes, many of the operations may be performed in parallel or simultaneously. In addition, the order of operations may be rearranged. A process may have additional steps not included in the diagrams. Furthermore, the example methods may be implemented by hardware, software, firmware, middleware, microcode, hardware description languages, or any combination thereof. When implemented in software, firmware, middleware, or microcode, the program code or code segments to perform the necessary tasks may be stored in a non-transitory computer-readable medium, such as a storage medium. A processor may perform the tasks described.

[0229] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly or conventionally understood. As used herein, the articles "a" and "an" refer to one or more than one (i.e., at least one) of the grammatical object of the article. By way of example, "an element" means one element or more than one element. As used herein, "about" and / or "approximately" when referring to a measurable value, such as an amount, duration, etc., encompasses a variation of ±20% or ±10%, ±5%, or ±0.1% from the specified value, when such variation is appropriate in the context of the systems, devices, circuits, methods, and other implementations described herein. "Substantially" as used herein when referring to a measurable value such as an amount, duration, physical attribute (such as frequency), etc., also encompasses variations of ±20%, ±10%, ±5%, or +0.1% from the specified value, where such variations are appropriate in the context of the systems, devices, circuits, methods, and other implementations described herein.

[0230] As used herein, including the claims, "or" used in a list of items ending with "at least one of" or "one or more of" indicates a disjunctive list, such as, for example, a list of "at least one of A, B, or C" means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) or a combination of two or more features (e.g., AA, AAB, ABBC, etc.). Also, as used herein, unless expressly stated otherwise, a statement that a function or operation is "based on" an item or condition means that the function or operation is based on the stated item or condition, and may be based on one or more items and / or conditions in addition to the stated item or condition.

[0231] As used herein, a mobile device, user equipment (UE), or mobile station (MS) refers to a device such as a cellular or other wireless communication device, a smartphone, a tablet, a personal communication system (PCS) device, a personal navigation device (PND), a personal information manager (PIM), a personal digital assistant (PDA), a laptop, or other suitable mobile device capable of receiving wireless communication and / or navigation signals, such as navigation positioning signals. The term "mobile station" (or "mobile device", "wireless device", or "user equipment") is also intended to include devices that communicate with a personal navigation device (PND), such as by a short-range wireless connection, an infrared connection, a wireline connection, or other connection, regardless of whether satellite signal reception, assistance data reception, and / or position-related processing occurs in the device or in the PND. Additionally, a "mobile station" or "user equipment" is intended to include all devices, including wireless communication devices, computers, laptops, tablet devices, etc., capable of communicating with a server over the Internet, Wi-Fi, or other networks, etc., for communicating with one or more types of nodes, whether the satellite signal reception, assistance data reception, and / or location related processing occurs on the device, on a server, or on another device or node associated with the network. Any operable combination of the above is considered a "mobile station" or "user equipment." A mobile device or user equipment (UE) may be referred to as a mobile terminal, terminal, device, secure user plane location enabled terminal (SET), target device, target, or by some other name.

[0232] In one embodiment, a first exemplary independent claim may comprise a method for supporting location of a user equipment (UE) at a first wireless node, comprising: receiving a first request for broadcasting more location related information, the broadcasting based on a wireless access type for the first wireless node; and broadcasting the more location related information using the wireless access type and based on the first request.

[0233] While some of the techniques, processes, and / or implementations presented herein may comply with all or a portion of one or more standards, such techniques, processes, and / or implementations, in some embodiments, may not comply with all or a portion of such one or more standards.

[0234] In view of this description, embodiments may include different combinations of features. Example implementations are described in the following numbered clauses.

[0235] Clause 1: A method, implemented by a user equipment (UE), for supporting sidelink (SL) positioning of a plurality of other UEs, comprising: sending a first Sidelink Positioning Protocol (SLPP) message to all UEs of the plurality of other UEs; receiving a second SLPP message from each UE of the plurality of other UEs, the second SLPP message received from each UE including an SLPP capability of each UE and an SLPP resource of each UE; exchanging additional SLPP messages with at least some UEs among the plurality of other UEs, the additional SLPP message being based on the SLPP capabilities and SLPP resources of each of at least some of the UEs; and determining a location result for at least some of the UEs based on the additional SLPP message.

[0236] Clause 2: The method of clause 1, wherein the location result includes a range between a pair of UEs, a direction from the UE to another UE, a location of the UE relative to a location of another UE, a velocity of the UE, a relative velocity of the UE relative to another UE, or any combination thereof.

[0237] Clause 3: The method of clause 1 or 2, wherein sending a first SLPP message to all UEs of the plurality of other UEs, receiving a second SLPP message from each UE of the plurality of other UEs, and exchanging additional SLPP messages with at least some UEs in the plurality of other UEs is based on SL multicast when the plurality of other UEs includes two or more UEs.

[0238] Clause 4: The method according to any one of clauses 1 to 3, wherein the first SLPP message includes the SLPP capability and SLPP resources of the UE.

[0239] Clause 5: The method according to any one of clauses 1 to 4, wherein the UE SLPP capability provides an indication of SLPP capabilities that are implemented to be supported by the UE.

[0240] Clause 6: A method according to any one of clauses 1 to 5, wherein the SLPP resources of the UE provide an indication of SLPP capabilities that the UE is permitted to support, SLPP capabilities that the UE is not permitted to support, or both.

[0241] Clause 7: The method of clause 6, wherein the SLPP capabilities that the UE is permitted or not permitted to support include permission or restriction on SL positioning reference signal (PRS) transmission time, permission or restriction on SL PRS measurement time, permission or restriction on SL PRS transmission duration, permission or restriction on SL PRS measurement duration, permission or restriction on bandwidth of SL PRS transmission, permission or restriction on bandwidth of the SL PRS being measured, permission or restriction on RF frequency of SL PRS transmission, permission or restriction on RF frequency of the SL PRS being measured, permission or restriction on signal coding of SL PRS transmission, permission or restriction on signal coding of the SL PRS being measured, permission or restriction on periodicity of SL PRS transmission, permission or restriction on periodicity of SL PRS measurement, permission or restriction on transmit power for SL PRS transmission, permission or restriction on transmit power for the SL PRS being measured, or any combination thereof.

[0242] Clause 8: The method of any one of clauses 1 to 7, wherein the second SLPP message received from each UE further includes SLPP service requirements of each UE, and the additional SLPP message is further based on the SLPP service requirements of each UE in at least some of the UEs.

[0243] Clause 9: The method according to clause 8, wherein the first SLPP message further includes an SLPP service requirement of the UE.

[0244] Clause 10: The method of clause 8, wherein the SLPP service requirements of the UE include an indication of instant location, deferred location, periodic location, triggered location, relative location, global location, location accuracy, location latency, location periodicity, location reliability, or any combination thereof.

[0245] Clause 11: A user equipment (UE), configured to support sidelink (SL) positioning of a plurality of other UEs, comprising: a wireless transceiver configured to communicate wirelessly with a network entity; at least one memory; and at least one processor coupled to the wireless transceiver and the at least one memory, wherein the at least one processor is configured to: send a first Sidelink Positioning Protocol (SLPP) message to all UEs of the plurality of other UEs via the wireless transceiver; receive a second SLPP message from each UE of the plurality of other UEs via the wireless transceiver, wherein the second SLPP message received from each UE includes an SLPP capability of each UE and an SLPP resource of each UE; exchange additional SLPP messages with at least some UEs in the plurality of other UEs via the wireless transceiver, the additional SLPP message being based on the SLPP capability and the SLPP resource of each of at least some of the UEs; and determine a location result for at least some of the UEs based on the additional SLPP message.

[0246] Clause 12: The UE described in Clause 11, wherein to determine a location result, at least one processor is configured to determine a range between a pair of UEs, a direction from the UE to another UE, a location of the UE relative to a location of another UE, a velocity of the UE, a relative velocity of the UE relative to another UE, or any combination thereof.

[0247] Clause 13: A UE as described in clause 11 or 12, wherein at least one processor is configured to, when the plurality of other UEs includes two or more UEs, send a first SLPP message to all UEs of the plurality of other UEs based on SL multicast, receive a second SLPP message from each UE of the plurality of other UEs, and exchange additional SLPP messages with at least some UEs in the plurality of other UEs.

[0248] Clause 14: The UE according to any one of clauses 11 to 13, wherein the first SLPP message includes SLPP capabilities and SLPP resources of the UE.

[0249] Clause 15: The UE according to any one of clauses 11 to 14, wherein the UE SLPP capability provides an indication of SLPP capabilities that are implemented to be supported by the UE.

[0250] Clause 16: A UE as described in any one of clauses 11 to 15, wherein the UE's SLPP resources provide an indication of SLPP capabilities that the UE is authorized to support, SLPP capabilities that the UE is not authorized to support, or both.

[0251] Clause 17: The UE described in Clause 16, wherein the SLPP capabilities that the UE is permitted or not permitted to support include permission or restriction on SL positioning reference signal (PRS) transmission time, permission or restriction on SL PRS measurement time, permission or restriction on SL PRS transmission duration, permission or restriction on SL PRS measurement duration, permission or restriction on bandwidth of SL PRS transmission, permission or restriction on bandwidth of the SL PRS being measured, permission or restriction on RF frequency of SL PRS transmission, permission or restriction on RF frequency of the SL PRS being measured, permission or restriction on signal coding of SL PRS transmission, permission or restriction on signal coding of the SL PRS being measured, permission or restriction on periodicity of SL PRS transmission, permission or restriction on periodicity of SL PRS measurement, permission or restriction on transmit power for SL PRS transmission, permission or restriction on transmit power for the SL PRS being measured, or any combination thereof.

[0252] Clause 18: A UE described in any one of clauses 11 to 17, wherein the second SLPP message received from each UE further includes SLPP service requirements of each UE, and the additional SLPP message is further based on the SLPP service requirements of each UE in at least some of the UEs.

[0253] Clause 19: The UE according to clause 18, wherein the first SLPP message further includes an SLPP service requirement of the UE.

[0254] Clause 20: The UE of clause 18, wherein the SLPP service requirements of the UE include an indication of instant location, deferred location, periodic location, triggered location, relative location, global location, location accuracy, location latency, location periodicity, location reliability, or any combination thereof.

[0255] Clause 21: A user equipment (UE), configured to support sidelink (SL) positioning of a plurality of other UEs, comprising: means for sending a first Sidelink Positioning Protocol (SLPP) message to all UEs of the plurality of other UEs; means for receiving a second SLPP message from each UE of the plurality of other UEs, the second SLPP message received from each UE including an SLPP capability of each UE and an SLPP resource of each UE; means for exchanging additional SLPP messages with at least some UEs of the plurality of other UEs, the additional SLPP messages being based on the SLPP capabilities and SLPP resources of each of at least some of the UEs; and means for determining a location result for at least some of the UEs based on the additional SLPP messages.

[0256] Clause 22: The UE of clause 21, wherein the means for determining a location result comprises means for determining a range between a pair of UEs, a direction from the UE to another UE, a location of the UE relative to a location of another UE, a velocity of the UE, a relative velocity of the UE relative to another UE, or any combination thereof.

[0257] Clause 23: A UE as described in clause 21 or 22, wherein sending a first SLPP message to all UEs of the plurality of other UEs, receiving a second SLPP message from each UE of the plurality of other UEs, and exchanging additional SLPP messages with at least some UEs in the plurality of other UEs is based on SL multicast when the plurality of other UEs includes two or more UEs.

[0258] Clause 24: The UE according to any one of clauses 21 to 23, wherein the first SLPP message includes SLPP capabilities and SLPP resources of the UE.

[0259] Clause 25: The UE according to any one of clauses 21 to 24, wherein the UE SLPP capability provides an indication of SLPP capabilities that are implemented to be supported by the UE.

[0260] Clause 26: A UE as described in any one of clauses 21 to 25, wherein the UE's SLPP resources provide an indication of SLPP capabilities that the UE is authorized to support, SLPP capabilities that the UE is not authorized to support, or both.

[0261] Clause 27: The UE described in Clause 26, wherein the SLPP capabilities that the UE is permitted or not permitted to support include permission or restriction on SL positioning reference signal (PRS) transmission time, permission or restriction on SL PRS measurement time, permission or restriction on SL PRS transmission duration, permission or restriction on SL PRS measurement duration, permission or restriction on bandwidth of SL PRS transmission, permission or restriction on bandwidth of the SL PRS being measured, permission or restriction on RF frequency of SL PRS transmission, permission or restriction on RF frequency of the SL PRS being measured, permission or restriction on signal coding of SL PRS transmission, permission or restriction on signal coding of the SL PRS being measured, permission or restriction on periodicity of SL PRS transmission, permission or restriction on periodicity of SL PRS measurement, permission or restriction on transmit power for SL PRS transmission, permission or restriction on transmit power for the SL PRS being measured, or any combination thereof.

[0262] Clause 28: A UE described in any one of clauses 21 to 27, wherein the second SLPP message received from each UE further includes SLPP service requirements of each UE, and the additional SLPP message is further based on the SLPP service requirements of each UE in at least some of the UEs.

[0263] Clause 29: The UE as described in clause 28, wherein the first SLPP message further includes an SLPP service requirement of the UE.

[0264] Clause 30: The UE of clause 28, wherein the SLPP service requirements of the UE include an indication of instant location, deferred location, periodic location, triggered location, relative location, global location, location accuracy, location latency, location periodicity, location reliability, or any combination thereof.

[0265] Clause 31: A non-transitory storage medium having program code stored thereon, the program code being operable to configure at least one processor in a user equipment (UE) to support sidelink (SL) positioning of a plurality of other UEs, the program code including instructions for: sending a first Sidelink Positioning Protocol (SLPP) message to all UEs of the plurality of other UEs; receiving a second SLPP message from each UE of the plurality of other UEs, the second SLPP message received from each UE including an SLPP capability of each UE and an SLPP resource of each UE; exchanging additional SLPP messages with at least some UEs of the plurality of other UEs, the additional SLPP message being based on the SLPP capabilities and SLPP resources of each of at least some of the UEs; and determining a location result for at least some of the UEs based on the additional SLPP message.

[0266] Clause 32: A non-transitory storage medium as described in clause 31, wherein the instructions for determining a location result include instructions for determining a range between a pair of UEs, a direction from the UE to another UE, a location of the UE relative to a location of another UE, a velocity of the UE, a relative velocity of the UE relative to another UE, or any combination thereof.

[0267] Clause 33: A non-transitory storage medium as described in clause 31 or 32, wherein the program code includes instructions for sending a first SLPP message to all UEs of the plurality of other UEs based on SL multicast when the plurality of other UEs includes two or more UEs, receiving a second SLPP message from each UE of the plurality of other UEs, and exchanging additional SLPP messages with at least some UEs in the plurality of other UEs.

[0268] Clause 34: A non-transitory storage medium according to any one of clauses 31 to 33, wherein the first SLPP message includes the UE's SLPP capabilities and SLPP resources.

[0269] Clause 35: A non-transitory storage medium according to any one of clauses 31 to 34, wherein the UE SLPP capabilities provide an indication of SLPP capabilities that are implemented to be supported by the UE.

[0270] Clause 36: A non-transitory storage medium as described in any one of clauses 31 to 35, providing an indication of SLPP capabilities that the UE is authorized to support, SLPP capabilities that the UE is not authorized to support, or both.

[0271] Clause 37: The non-transitory storage medium of clause 36, wherein the SLPP capabilities that the UE is permitted or not permitted to support include permission or restriction on SL positioning reference signal (PRS) transmission time, permission or restriction on SL PRS measurement time, permission or restriction on SL PRS transmission duration, permission or restriction on SL PRS measurement duration, permission or restriction on bandwidth of SL PRS transmission, permission or restriction on bandwidth of the SL PRS being measured, permission or restriction on RF frequency of SL PRS transmission, permission or restriction on RF frequency of the SL PRS being measured, permission or restriction on signal coding of SL PRS transmission, permission or restriction on signal coding of the SL PRS being measured, permission or restriction on periodicity of SL PRS transmission, permission or restriction on periodicity of SL PRS measurement, permission or restriction on transmit power for SL PRS transmission, permission or restriction on transmit power for the SL PRS being measured, or any combination thereof.

[0272] Clause 38: A non-transitory storage medium according to any one of clauses 31 to 37, wherein the second SLPP message received from each UE further includes SLPP service requirements of each UE, and the additional SLPP message is further based on the SLPP service requirements of each UE in at least some of the UEs.

[0273] Clause 39: The non-transitory storage medium according to clause 38, wherein the first SLPP message further includes an SLPP service requirement of the UE.

[0274] Clause 40: A non-transitory storage medium as described in clause 38, wherein the UE's SLPP service requirements include an indication of instant location, deferred location, periodic location, triggered location, relative location, global location, location accuracy, location latency, location periodicity, location reliability, or any combination thereof.

[0275] Clause 41: A method for determining a group of UEs performing sidelink (SL) positioning, performed by a user equipment (UE) according to the present disclosure, may include: discovering a plurality of UEs available for SL positioning, including the UE; determining one or more group criteria parameters; and determining a group status indication for at least one UE among the plurality of UEs based on the one or more group criteria parameters, wherein the group status indication for the at least one UE indicates inclusion or exclusion of at least one UE in the group.

[0276] Clause 42: The method of clause 41, wherein the at least one UE is included in the group when the group status indication for the at least one UE indicates including the at least one UE in the group, and the at least one UE is excluded from the group when the group status indication for the at least one UE indicates excluding the at least one UE from the group.

[0277] Clause 43: The method of clause 41, wherein each of the other UEs in the plurality of UEs determines a group status indication for the at least one UE based on group criteria parameters obtained by each of the other UEs from the UE or from other UEs in the plurality of UEs, and the at least one UE is included in or excluded from the group based on the group status indication for the at least one UE determined by each of the UEs in the plurality of UEs.

[0278] Clause 44: The method of any one of clauses 41 to 43, wherein the one or more group criteria parameters include a distance restriction, a time restriction, a travel direction restriction, a speed restriction, or any combination thereof.

[0279] Clause 45: The method of any one of clauses 41 to 44, wherein the one or more group criteria parameters include a SL positioning method restriction, a SL positioning method type restriction, or both.

[0280] Clause 46: A user equipment (UE) configured to determine a group of UEs to perform side link (SL) positioning, comprising: a wireless transceiver configured to communicate wirelessly with a network entity; at least one memory; and at least one processor coupled to the wireless transceiver and the at least one memory, wherein the at least one processor is configured to: discover, via the wireless transceiver, a plurality of UEs that are available for SL positioning, including the UE; determine one or more group criteria parameters; and determine a group status indication for at least one UE among the plurality of UEs based on the one or more group criteria parameters, wherein the group status indication for the at least one UE indicates inclusion of at least one UE in the group or exclusion of at least one UE from the group.

[0281] Clause 47: The UE described in Clause 46, wherein the at least one UE is included in the group when a group status indication for the at least one UE indicates to include the at least one UE in the group, and the at least one UE is excluded from the group when a group status indication for the at least one UE indicates to exclude the at least one UE from the group.

[0282] Clause 48: The UE described in Clause 46, wherein each of the other UEs in the plurality of UEs determines a group status indication for the at least one UE based on group criteria parameters obtained by each of the other UEs from the UE or from other UEs in the plurality of UEs, and the at least one UE is included in or excluded from the group based on the group status indication for the at least one UE determined by each of the UEs in the plurality of UEs.

[0283] Clause 49: The UE according to any one of clauses 46 to 48, wherein the one or more group criteria parameters include a distance restriction, a time restriction, a movement direction restriction, a speed restriction, or any combination thereof.

[0284] Clause 50: The UE of any one of clauses 46 to 49, wherein the one or more group criteria parameters include a SL positioning method restriction, a SL positioning method type restriction, or both.

[0285] Clause 51: A user equipment (UE), configured to determine a group of UEs that perform sidelink (SL) positioning, comprising: means for discovering a plurality of UEs that are available for SL positioning, including the UE; means for determining one or more group criteria parameters; and means for determining a group status indication for at least one UE among the plurality of UEs based on the one or more group criteria parameters, wherein the group status indication for the at least one UE indicates inclusion of at least one UE in the group or exclusion of at least one UE from the group.

[0286] Clause 52: The UE described in Clause 51, wherein the at least one UE is included in the group when a group status indication for the at least one UE indicates to include the at least one UE in the group, and the at least one UE is excluded from the group when a group status indication for the at least one UE indicates to exclude the at least one UE from the group.

[0287] Clause 53: The UE described in Clause 51, wherein each of the other UEs in the plurality of UEs determines a group status indication for the at least one UE based on group criteria parameters obtained by each of the other UEs from the UE or from other UEs in the plurality of UEs, and the at least one UE is included in or excluded from the group based on the group status indication for the at least one UE determined by each of the UEs in the plurality of UEs.

[0288] Clause 54: The UE of any one of clauses 51 to 53, wherein the one or more group criteria parameters include a distance restriction, a time restriction, a movement direction restriction, a speed restriction, or any combination thereof.

[0289] Clause 55: The UE of any one of clauses 51 to 54, wherein the one or more group criteria parameters include a SL positioning method restriction, a SL positioning method type restriction, or both.

[0290] Clause 56: A non-transitory storage medium having program code stored thereon, the program code being operable to configure at least one processor in a user equipment (UE) to determine a group of UEs that perform sidelink (SL) positioning, the program code including instructions for discovering a plurality of UEs that are available for SL positioning, including the UE, determining one or more group criteria parameters, and determining a group status indication for at least one UE in the plurality of UEs based on the one or more group criteria parameters, the group status indication for the at least one UE indicating inclusion of the at least one UE in the group or exclusion of the at least one UE from the group.

[0291] Clause 57: The non-transitory storage medium of clause 56, wherein the at least one UE is included in the group when a group status indication for the at least one UE indicates including the at least one UE in the group, and the at least one UE is excluded from the group when a group status indication for the at least one UE indicates excluding the at least one UE from the group.

[0292] Clause 58: A non-transitory storage medium as described in Clause 56, wherein each of the other UEs in the plurality of UEs determines a group status indication for the at least one UE based on group criteria parameters obtained by each of the other UEs from the UE or from other UEs in the plurality of UEs, and the at least one UE is included in or excluded from the group based on the group status indication for the at least one UE determined by each of the UEs in the plurality of UEs.

[0293] Clause 59: A non-transitory storage medium described in any one of clauses 56 to 58, wherein the one or more group criteria parameters include a distance restriction, a time restriction, a movement direction restriction, a speed restriction, or any combination thereof.

[0294] Clause 60: The non-transitory storage medium of any one of clauses 56 to 59, wherein the one or more group criteria parameters include a SL positioning method restriction, a SL positioning type restriction, or both.

[0295] Clause 61: A method, performed by a user equipment (UE), for enabling a group of UEs including the UE to perform sidelink positioning, comprising: sending to each other UE in the group an indication of reverse link communication from each UE in the group to the UE; receiving from each other UE in the group an indication of reverse link communication from each UE in the group to each other UE; and determining a group status indication for at least one UE in the group based on the indication of reverse link communication from each UE in the group to the UE and the indication of reverse link communication from each UE in the group to each other UE in the group, wherein the group status indication for the at least one UE indicates inclusion or exclusion of at least one UE in the group.

[0296] Clause 62: The method of clause 61, wherein sending an indication of reverse link communication to each of the other UEs in the group and receiving an indication of reverse link communication from each of the other UEs in the group is based on SL multicast when the group includes three or more UEs.

[0297] Clause 63: The method of clause 61 or 62, wherein the indication of reverse link communication from any UE in the group to any other UE in the group indicates whether SL Positioning Protocol (SLPP) signaling transmitted by any UE has been received or not received by any other UE.

[0298] Clause 64: The method of clause 63, wherein the SLPP signaling includes a SLPP message, a SL positioning reference signal (PRS), or both.

[0299] Clause 65: The method according to any one of clauses 61 to 64, wherein the at least one UE is included in the group when the group status indication of the at least one UE indicates to include the at least one UE in the group, and the at least one UE is excluded from the group when the group status indication of the at least one UE indicates to exclude the at least one UE from the group.

[0300] Clause 66: The method according to any one of clauses 61 to 65, wherein each of the other UEs in the group determines a group status indication for the at least one UE based on an indication of reverse link communication received from the other UEs in the group, and the at least one UE is included in or excluded from the group based on the group status indication for the at least one UE determined by each of the UEs in the group.

[0301] Clause 67: The method of any one of clauses 61 to 66, further comprising: determining a status of forward link communication and a status of reverse link communication between all pairs of UEs in the group based on an indication of reverse link communication from each UE in the group to the UE and an indication of reverse link communication from each UE in the group to each other UE in the group; and determining a group status indication for at least one UE based on the status of forward link communication and the status of reverse link communication between all pairs of UEs in the group.

[0302] Clause 68: The method described in clause 67, wherein the status of forward link communication and the status of reverse link communication between any pair of UEs in the group indicate, for each of the forward transfer direction and the reverse transfer direction, whether successful SLPP signaling transfer between the pair of UEs is currently possible, is currently not possible, or has an unknown status.

[0303] Clause 69: The method according to any one of clauses 61 to 68, wherein the indication of reverse link communication is an implicit indication, and it is assumed that reverse link communication from the first UE to the second UE exists when the second UE reports one or more measurements obtained by the second UE for the sidelink PRS transmitted by the first UE, and it is assumed that reverse link communication from the first UE to the second UE does not exist when the second UE does not report any measurements obtained by the second UE for the sidelink PRS transmitted by the first UE or when the second UE provides an indication that it was not able to obtain any measurements for the SL PRS transmitted by the first UE.

[0304] Clause 70: A user equipment (UE), configured to enable a group of UEs including the UE to perform sidelink positioning, comprising: a wireless transceiver configured to communicate wirelessly with a network entity; at least one memory; and at least one processor coupled to the wireless transceiver and the at least one memory, wherein the at least one processor is configured to: send, via the wireless transceiver, to each of other UEs in the group, an indication of reverse link communication from each UE in the group to the UE; receive, via the wireless transceiver, from each of the other UEs in the group, an indication of reverse link communication from each UE in the group to each of the other UEs in the group; and determine a group status indication for at least one UE in the group based on the indication of reverse link communication from each UE in the group to the UE and the indication of reverse link communication from each UE in the group to each of the other UEs in the group, wherein the group status indication for the at least one UE indicates inclusion of at least one UE in the group or exclusion of at least one UE from the group.

[0305] Clause 71: The UE described in Clause 70, wherein at least one processor is configured to, when the group includes three or more UEs, send an indication of reverse link communication to each of the other UEs in the group based on SL multicast, and receive an indication of reverse link communication from each of the other UEs in the group.

[0306] Clause 72: A UE as described in clause 70 or 71, wherein the indication of reverse link communication from any UE in the group to any other UE in the group indicates whether SL Positioning Protocol (SLPP) signaling transmitted by any UE has been received or not received by any other UE.

[0307] Clause 73: The UE of clause 72, wherein the SLPP signaling includes a SLPP message, a SL positioning reference signal (PRS), or both.

[0308] Clause 74: A UE according to any one of clauses 70 to 73, wherein the at least one UE is included in the group when a group status indication of the at least one UE indicates to include the at least one UE in the group, and the at least one UE is excluded from the group when a group status indication of the at least one UE indicates to exclude the at least one UE from the group.

[0309] Clause 75: A UE described in any one of clauses 70 to 74, wherein each of the other UEs in the group determines a group status indication for the at least one UE based on an indication of reverse link communication received from the other UEs in the group, and the at least one UE is included in or excluded from the group based on the group status indication for the at least one UE determined by each of the UEs in the group.

[0310] Clause 76: A UE described in any one of Clauses 70 to 75, further configured to: determine a status of forward link communication and a status of reverse link communication between all pairs of UEs in the group based on an indication of reverse link communication from each UE in the group to the UE and an indication of reverse link communication from each UE in the group to each other UE in the group; and determine a group status indication for at least one UE based on the status of forward link communication and the status of reverse link communication between all pairs of UEs in the group.

[0311] Clause 77: A UE as described in Clause 76, wherein the status of forward link communication and the status of reverse link communication between any pair of UEs in the group indicate, for each of the forward transfer direction and the reverse transfer direction, whether successful SLPP signaling transfer between the pair of UEs is currently possible, currently not possible, or has an unknown status.

[0312] Clause 78: A UE as described in any one of Clauses 70 to 77, wherein the indication of reverse link communication is an implicit indication, and it is assumed that reverse link communication from the first UE to the second UE exists when the second UE reports one or more measurements obtained by the second UE for the sidelink PRS transmitted by the first UE, and it is assumed that reverse link communication from the first UE to the second UE does not exist when the second UE does not report any measurements obtained by the second UE for the sidelink PRS transmitted by the first UE or when the second UE provides an indication that it was not able to obtain any measurements for the SL PRS transmitted by the first UE.

[0313] Clause 79: A user equipment (UE), configured to enable a group of UEs including the UE to perform sidelink positioning, comprising: means for sending to each of other UEs in the group an indication of reverse link communication from each UE in the group to the UE; means for receiving from each of the other UEs in the group an indication of reverse link communication from each UE in the group to each of the other UEs; and means for determining a group status indication for at least one UE in the group based on the indication of reverse link communication from each UE in the group to the UE and the indication of reverse link communication from each UE in the group to each of the other UEs in the group, wherein the group status indication for the at least one UE indicates inclusion of at least one UE in the group or exclusion of at least one UE from the group.

[0314] Clause 80: The UE described in clause 79, wherein the means for sending an indication of reverse link communication to each of the other UEs in the group and the means for receiving an indication of reverse link communication from each of the other UEs in the group are based on SL multicast when the group includes three or more UEs.

[0315] Clause 81: A UE as described in clause 79 or 80, wherein the indication of reverse link communication from any UE in the group to any other UE in the group indicates whether SL Positioning Protocol (SLPP) signaling transmitted by any UE has been received or not received by any other UE.

[0316] Clause 82: The UE of clause 81, wherein the SLPP signaling includes a SLPP message, a SL positioning reference signal (PRS), or both.

[0317] Clause 83: A UE according to any one of clauses 79 to 82, wherein the at least one UE is included in the group when a group status indication of the at least one UE indicates to include the at least one UE in the group, and the at least one UE is excluded from the group when a group status indication of the at least one UE indicates to exclude the at least one UE from the group.

[0318] Clause 84: A UE described in any one of clauses 79 to 83, wherein each of the other UEs in the group determines a group status indication for the at least one UE based on an indication of reverse link communication received from the other UEs in the group, and the at least one UE is included in or excluded from the group based on the group status indication for the at least one UE determined by each of the UEs in the group.

[0319] Clause 85: A UE described in any one of clauses 79 to 84, further comprising: means for determining a status of forward link communication and a status of reverse link communication between all pairs of UEs in the group based on an indication of reverse link communication from each UE in the group to the UE and an indication of reverse link communication from each UE in the group to each other UE in the group; and means for determining a group status indication for at least one UE based on the status of forward link communication and the status of reverse link communication between all pairs of UEs in the group.

[0320] Clause 86: A UE as described in Clause 85, wherein the status of forward link communication and the status of reverse link communication between any pair of UEs in the group indicate, for each of the forward transfer direction and the reverse transfer direction, whether successful SLPP signaling transfer between the pair of UEs is currently possible, currently not possible, or has an unknown status.

[0321] Clause 87: A UE described in any one of clauses 79 to 86, wherein the indication of reverse link communication is an implicit indication, and it is assumed that reverse link communication from the first UE to the second UE exists when the second UE reports one or more measurements obtained by the second UE for a sidelink PRS transmitted by the first UE, and it is assumed that reverse link communication from the first UE to the second UE does not exist when the second UE does not report any measurements obtained by the second UE for a sidelink PRS transmitted by the first UE or when the second UE provides an indication that it was not able to obtain any measurements for a SL PRS transmitted by the first UE.

[0322] Clause 88: A non-transitory storage medium having program code stored thereon, the program code being operable to configure at least one processor in a user equipment (UE) to enable a group of UEs including the UE to perform sidelink positioning, the program code including instructions for sending to each other UE in the group an indication of reverse link communication from each UE in the group to the UE, and receiving from each other UE in the group an indication of reverse link communication from each UE in the group to each other UE, and determining a group status indication for at least one UE in the group based on the indication of reverse link communication from each UE in the group to the UE and the indication of reverse link communication from each UE in the group to each other UE in the group, the group status indication for the at least one UE indicating inclusion of at least one UE in the group or exclusion of at least one UE from the group.

[0323] Clause 89: A non-transitory storage medium as described in clause 88, wherein at least one processor is configured to, when the group includes three or more UEs, send an indication of reverse link communication to each of the other UEs in the group based on SL multicast and receive an indication of reverse link communication from each of the other UEs in the group.

[0324] Clause 90: A non-transitory storage medium as described in clause 88 or 89, wherein the indication of reverse link communication from any UE in the group to any other UE in the group indicates whether SL Positioning Protocol (SLPP) signaling transmitted by any UE has been received or not received by any other UE.

[0325] Clause 91: The non-transitory storage medium of clause 90, wherein the SLPP signaling includes an SLPP message, an SL positioning reference signal (PRS), or both.

[0326] Clause 92: A non-transitory storage medium according to any one of clauses 88 to 91, wherein at least one UE is included in the group when a group status indication of at least one UE indicates to include at least one UE in the group, and at least one UE is excluded from the group when a group status indication of at least one UE indicates to exclude at least one UE from the group.

[0327] Clause 93: A non-transitory storage medium described in any one of clauses 88 to 92, wherein each of the other UEs in the group determines a group status indication for the at least one UE based on an indication of reverse link communication received from the other UEs in the group, and the at least one UE is included in or excluded from the group based on the group status indication for the at least one UE determined by each of the UEs in the group.

[0328] Clause 94: The non-transitory storage medium of any one of clauses 88 to 93, wherein the program code further includes instructions for determining a status of forward link communication and a status of reverse link communication between all pairs of UEs in the group based on an indication of reverse link communication from each UE in the group to the UE and an indication of reverse link communication from each UE in the group to each other UE in the group, and determining a group status indication for at least one UE based on the status of forward link communication and the status of reverse link communication between all pairs of UEs in the group.

[0329] Clause 95: A non-transitory storage medium as described in clause 94, wherein the status of forward link communication and the status of reverse link communication between any pair of UEs in the group indicate, for each of the forward transfer direction and the reverse transfer direction, whether successful SLPP signaling transfer between the pair of UEs is currently possible, is currently not possible, or has an unknown status.

[0330] Clause 96: A non-transitory storage medium according to any one of clauses 88 to 95, wherein the indication of reverse link communication is an implicit indication, and it is assumed that reverse link communication from the first UE to the second UE exists when the second UE reports one or more measurements obtained by the second UE for the sidelink PRS transmitted by the first UE, and it is assumed that reverse link communication from the first UE to the second UE does not exist when the second UE does not report any measurements obtained by the second UE for the sidelink PRS transmitted by the first UE or when the second UE provides an indication that it was not able to obtain any measurements for the SL PRS transmitted by the first UE.

[0331] Clause 97: A method, implemented by a user equipment (UE), for enabling a first group of UEs including the UE and a second group of UEs including the UE to perform sidelink positioning, comprising: obtaining location results for a first set of UEs in the first group that do not belong to the second group; obtaining location results for a second set of UEs in the second group that do not belong to the first group; and causing, based on the location results for the first set of UEs and the second set of UEs, to add or transfer at least some of the first set of UEs to the second group, to add or transfer at least some of the second set of UEs to the first group, or both.

[0332] Clause 98: The method of clause 97, wherein the location results for the first set of UEs and the second set of UEs include a range between the pair of UEs, a direction from the UE to another UE, a location of the UE relative to a location of the other UE, a velocity of the UE, a relative velocity of the UE relative to another UE, or any combination thereof.

[0333] Clause 99: The method of clause 97 or 98, wherein the addition or transfer of at least some of the first set of UEs or at least some of the second set of UEs merges the first group with the second group.

[0334] Clause 100: A user equipment (UE), configured to enable a first group of UEs including the UE and a second group of UEs including the UE to perform sidelink positioning, the UE comprising: a wireless transceiver configured to communicate wirelessly with a network entity; at least one memory; and at least one processor coupled to the wireless transceiver and the at least one memory, wherein the at least one processor is configured to: obtain location results for a first set of UEs in the first group that do not belong to the second group; obtain location results for a second set of UEs in the second group that do not belong to the first group; and cause, based on the location results for the first set of UEs and the second set of UEs, to add or transfer at least some of the first set of UEs to the second group, to add or transfer at least some of the second set of UEs to the first group, or both.

[0335] Clause 101: The UE described in Clause 100, wherein to obtain location results for a first set of UEs and a second set of UEs, the one or more processors are configured to obtain a range between a pair of UEs, a direction from the UE to another UE, a location of the UE relative to a location of the other UE, a velocity of the UE, a relative velocity of the UE relative to another UE, or any combination thereof.

[0336] Clause 102: The UE of clause 100 or 101, wherein the addition or transfer of at least some of the first set of UEs or at least some of the second set of UEs merges the first group with the second group.

[0337] Clause 103: A user equipment (UE), configured to enable a first group of UEs including the UE and a second group of UEs including the UE to perform sidelink positioning, comprising: means for acquiring relative locations and velocities of a first set of UEs in the first group that do not belong to the second group; means for acquiring relative locations and velocities of a second set of UEs in the second group that do not belong to the first group; and means for causing an addition or transfer of at least some of the first set of UEs to the second group, an addition or transfer of at least some of the second set of UEs to the first group, or both, based on the relative locations and velocities of the first set of UEs and the second set of UEs.

[0338] Clause 104: The UE described in Clause 103, wherein the means for obtaining location results for a first set of UEs and the means for obtaining location results for a second set of UEs comprise means for obtaining a range between a pair of UEs, a direction from the UE to another UE, a location of the UE relative to a location of the other UE, a velocity of the UE, a relative velocity of the UE relative to another UE, or any combination thereof.

[0339] Clause 105: The UE of clause 103 or 104, wherein the addition or transfer of at least some of the first set of UEs or at least some of the second set of UEs merges the first group with the second group.

[0340] Clause 106: A non-transitory storage medium having program code stored thereon, the program code being operable to configure at least one processor in a user equipment (UE) to enable a first group of UEs including the UE and a second group of UEs including the UE to perform sidelink positioning, the program code including instructions for obtaining relative locations and velocities of a first set of UEs in the first group that do not belong to the second group, obtaining relative locations and velocities of a second set of UEs in the second group that do not belong to the first group, and causing, based on the relative locations and velocities for the first set of UEs and the second set of UEs, to add or transfer at least some of the first set of UEs to the second group, to add or transfer at least some of the second set of UEs to the first group, or both.

[0341] Clause 107: The non-transitory storage medium of clause 106, wherein the code for obtaining location results for a first set of UEs and the code for obtaining location results for a second set of UEs comprise code for obtaining a range between a pair of UEs, a direction from the UE to another UE, a location of the UE relative to a location of another UE, a velocity of the UE, a relative velocity of the UE relative to another UE, or any combination thereof.

[0342] Clause 108: The non-transitory storage medium of clause 106 or 107, wherein the addition or transfer of at least some of the first set of UEs or at least some of the second set of UEs merges the first group with the second group.

[0343] Clause 109: A method implemented by a user equipment (UE) for supporting sidelink (SL) positioning for a group of UEs including the UE, comprising: receiving a first SL Positioning Protocol (SLPP) message from a first UE in the group; sending the first SLPP message to a location server in a public land mobile network (PLMN); receiving a second SLPP message from the location server in response to the first SLPP message; and sending the second SLPP message to other UEs in the group.

[0344] Clause 110: The method of clause 109, wherein sending a first SLPP message to the location server includes sending a first Long Term Evolution Positioning Protocol (LPP) message to the location server, the first LPP message including the first SLPP message, and receiving a second SLPP message from the location server includes receiving a second LPP message from the location server, the second LPP message including the second SLPP message.

[0345] Clause 111: The method of clause 109 or 110, wherein receiving a first SLPP message from a first UE in the group and sending a second SLPP message to other UEs in the group is based on SL multicast when the group of UEs includes three or more UEs.

[0346] Clause 112: The method according to any one of clauses 109 to 111, wherein the second SLPP message includes location results for one or more UEs in the group.

[0347] Clause 113: The method of clause 112, wherein the location results for one or more UEs in the group include a range between a pair of UEs, a direction from the UE to another UE, a location of the UE relative to a location of another UE, a velocity of the UE, a relative velocity of the UE with respect to another UE, or any combination thereof.

[0348] Clause 114: The method according to any one of clauses 109 to 113, wherein the first SLPP message includes SLPP capabilities, SLPP resources, or both for at least one other UE in the group.

[0349] Clause 115: The method according to any one of clauses 109 to 114, wherein the second SLPP message includes SLPP capabilities, SLPP resources, or both for the UE.

[0350] Clause 116: The method according to any one of clauses 109 to 115, wherein the first SLPP message includes a SL positioning reference signal (PRS) configuration for at least one UE in the group.

[0351] Clause 117: The method according to any one of clauses 109 to 116, wherein the second SLPP message includes a SL positioning reference signal (PRS) configuration for at least one UE in the group.

[0352] Clause 118: The method according to any one of clauses 109 to 117, wherein the first SLPP message includes SLPP measurement values ​​obtained by at least one UE in the group.

[0353] Clause 119: A method according to any one of clauses 109 to 118, wherein the location server includes a Location Management Function (LMF) or a Secure User Plane Location (SUPL) Location Platform (SLP).

[0354] Clause 120: The method of clause 119, wherein the location server includes an SLP, and the first SLPP message is sent to the location server as part of a first SUPL message, and the second SLPP message is received from the location server as part of a second SUPL message.

[0355] Clause 121: The method of clause 120, wherein the first SUPL message and the second SUPL message each include a SUPL POS message.

[0356] Clause 122: A user equipment (UE), configured to support side link (SL) positioning for a group of UEs including the UE, comprising: a wireless transceiver configured to communicate wirelessly with a network entity; at least one memory; and at least one processor coupled to the wireless transceiver and the at least one memory, wherein the at least one processor is configured to: receive a first SL Positioning Protocol (SLPP) message from a first UE in the group via the wireless transceiver; send the first SLPP message to a location server in a public land mobile network (PLMN) via the wireless transceiver; receive a second SLPP message from the location server via the wireless transceiver in response to the first SLPP message; and send the second SLPP message to other UEs in the group via the wireless transceiver.

[0357] Clause 123: A UE as described in Clause 122, wherein to send a first SLPP message to the location server, the one or more processors are configured to send a first Long Term Evolution Positioning Protocol (LPP) message to the location server, the first LPP message including the first SLPP message, and to receive a second SLPP message from the location server, the one or more processors are configured to receive a second LPP message from the location server, the second LPP message including the second SLPP message.

[0358] Clause 124: A UE as described in clause 122 or 123, wherein receiving a first SLPP message from a first UE in the group and sending a second SLPP message to other UEs in the group is based on SL multicast when the group of UEs includes three or more UEs.

[0359] Clause 125: A UE described in any one of clauses 122 to 124, wherein to receive a second SLPP message from the location server, one or more processors are configured to receive location results for one or more UEs in the group.

[0360] Clause 126: A UE as described in clause 125, wherein the location estimate for one or more UEs in the group includes a range between a pair of UEs, a direction from the UE to another UE, a location of the UE relative to a location of another UE, a velocity of the UE, a relative velocity of the UE relative to another UE, or any combination thereof.

[0361] Clause 127: The UE according to any one of clauses 122 to 126, wherein the first SLPP message includes SLPP capabilities, SLPP resources, or both for at least one other UE in the group.

[0362] Clause 128: The UE according to any one of clauses 122 to 127, wherein the second SLPP message includes SLPP capabilities, SLPP resources, or both for the UE.

[0363] Clause 129: The UE according to any one of clauses 122 to 128, wherein the first SLPP message includes a SL positioning reference signal (PRS) configuration for at least one UE in the group.

[0364] Clause 130: The UE according to any one of clauses 122 to 129, wherein the second SLPP message includes a SL positioning reference signal (PRS) configuration for at least one UE in the group.

[0365] Clause 131: A UE according to any one of clauses 122 to 130, wherein the first SLPP message includes SLPP measurement values ​​obtained by at least one UE in the group.

[0366] Clause 132: The UE according to any one of clauses 122 to 131, wherein the location server includes a Location Management Function (LMF) or a Secure User Plane Location (SUPL) Location Platform (SLP).

[0367] Clause 133: The UE of clause 132, wherein the location server includes an SLP, and the first SLPP message is sent to the location server as part of a first SUPL message, and the second SLPP message is received from the location server as part of a second SUPL message.

[0368] Clause 134: The UE of clause 133, wherein the first SUPL message and the second SUPL message each include a SUPL POS message.

[0369] Clause 135: A user equipment (UE), configured to support sidelink (SL) positioning for a group of UEs including the UE, comprising: means for receiving a first SL Positioning Protocol (SLPP) message from a first UE in the group; means for sending the first SLPP message to a location server in a public land mobile network (PLMN); means for receiving a second SLPP message from the location server in response to the first SLPP message; and means for sending the second SLPP message to other UEs in the group.

[0370] Clause 136: The UE described in Clause 135, wherein the means for sending a first SLPP message to the location server includes means for sending a first Long Term Evolution Positioning Protocol (LPP) message to the location server, the first LPP message including the first SLPP message, and the means for receiving a second SLPP message from the location server includes means for receiving a second LPP message from the location server, the second LPP message including the second SLPP message.

[0371] Clause 137: A UE as described in clause 135 or 136, wherein the means for receiving a first SLPP message from a first UE in the group and the means for sending a second SLPP message to other UEs in the group are based on SL multicast when the group of UEs includes three or more UEs.

[0372] Clause 138: The UE according to any one of clauses 135 to 137, wherein the means for receiving the second SLPP message from the location server includes means for receiving a location result for one or more UEs in the group.

[0373] Clause 139: A UE as described in clause 138, wherein the location estimate for one or more UEs in the group includes a range between a pair of UEs, a direction from the UE to another UE, a location of the UE relative to a location of another UE, a velocity of the UE, a relative velocity of the UE relative to another UE, or any combination thereof.

[0374] Clause 140: The UE according to any one of clauses 135 to 139, wherein the first SLPP message includes SLPP capabilities, SLPP resources, or both for at least one other UE in the group.

[0375] Clause 141: The UE according to any one of clauses 135 to 140, wherein the second SLPP message includes SLPP capabilities, SLPP resources, or both for the UE.

[0376] Clause 142: The UE according to any one of clauses 135 to 141, wherein the first SLPP message includes a SL positioning reference signal (PRS) configuration for at least one UE in the group.

[0377] Clause 143: The UE according to any one of clauses 135 to 142, wherein the second SLPP message includes a SL positioning reference signal (PRS) configuration for at least one UE in the group.

[0378] Clause 144: The UE according to any one of clauses 135 to 143, wherein the first SLPP message includes SLPP measurement values ​​obtained by at least one UE in the group.

[0379] Clause 145: The UE according to any one of clauses 135 to 144, wherein the location server includes a Location Management Function (LMF) or a Secure User Plane Location (SUPL) Location Platform (SLP).

[0380] Clause 146: The UE of clause 145, wherein the location server includes an SLP, and the first SLPP message is sent to the location server as part of a first SUPL message, and the second SLPP message is received from the location server as part of a second SUPL message.

[0381] Clause 147: The UE of clause 146, wherein the first SUPL message and the second SUPL message each include a SUPL POS message.

[0382] Clause 148: A non-transitory storage medium having program code stored thereon, the program code being operable to configure at least one processor in a user equipment (UE) to support sidelink (SL) positioning for a group of UEs including the UE, the program code including instructions for receiving a first SL Positioning Protocol (SLPP) message from a first UE in the group, sending the first SLPP message to a location server in a public land mobile network (PLMN), receiving a second SLPP message from the location server in response to the first SLPP message, and sending the second SLPP message to other UEs in the group.

[0383] Clause 149: A non-transitory storage medium as described in Clause 148, wherein the instructions for sending a first SLPP message to the location server include instructions for sending a first Long Term Evolution Positioning Protocol (LPP) message to the location server, the first LPP message including the first SLPP message, and the instructions for receiving a second SLPP message from the location server include instructions for receiving a second LPP message from the location server, the second LPP message including the second SLPP message.

[0384] Clause 150: A non-transitory storage medium as described in clause 148 or 149, wherein receiving a first SLPP message from a first UE in the group and sending a second SLPP message to other UEs in the group is based on SL multicast when the group of UEs includes three or more UEs.

[0385] Clause 151: A non-transitory storage medium according to any one of clauses 148 to 150, wherein the instructions for receiving a second SLPP message from the location server include instructions for receiving location results for one or more UEs in the group.

[0386] Clause 152: A non-transitory storage medium as described in clause 151, wherein the location estimate for one or more UEs in the group includes a range between a pair of UEs, a direction from the UE to another UE, a location of the UE relative to a location of another UE, a velocity of the UE, a relative velocity of the UE relative to another UE, or any combination thereof.

[0387] Clause 153: A non-transitory storage medium according to any one of clauses 148 to 152, wherein the first SLPP message includes SLPP capabilities, SLPP resources, or both for at least one other UE in the group.

[0388] Clause 154: A non-transitory storage medium according to any one of clauses 148 to 153, wherein the second SLPP message includes SLPP capabilities, SLPP resources, or both for the UE.

[0389] Clause 155: The non-transitory storage medium according to any one of clauses 148 to 154, wherein the first SLPP message includes a SL positioning reference signal (PRS) configuration for at least one UE in the group.

[0390] Clause 156: The non-transitory storage medium according to any one of clauses 148 to 155, wherein the second SLPP message includes a SL positioning reference signal (PRS) configuration for at least one UE in the group.

[0391] Clause 157: A non-transitory storage medium according to any one of clauses 148 to 156, wherein the first SLPP message includes SLPP measurement values ​​obtained by at least one UE in the group.

[0392] Clause 158: A non-transitory storage medium according to any one of clauses 148 to 157, wherein the location server includes a Location Management Function (LMF) or a Secure User Plane Location (SUPL) Location Platform (SLP).

[0393] Clause 159: A non-transitory storage medium as described in clause 158, wherein the location server includes an SLP, and the first SLPP message is sent to the location server as part of a first SUPL message, and the second SLPP message is received from the location server as part of a second SUPL message.

[0394] Clause 160: The non-transitory storage medium of clause 159, wherein the first SUPL message and the second SUPL message each include a SUPL POS message.

[0395] Although certain embodiments have been disclosed in detail herein, this is for illustrative purposes only and is not intended as a limitation on the scope of the appended claims. It is specifically contemplated that various substitutions, modifications, and alterations may be made therein without departing from the spirit and scope of the present disclosure as defined by the claims. Other aspects, advantages, and modifications are deemed to be within the scope of the following claims. The claims presented are representative of the embodiments and features disclosed herein. Other unclaimed embodiments and features are also contemplated. Accordingly, other embodiments are within the scope of the following claims.

Claims

1. A method for enabling a group of user equipment (UEs), including the UE, to perform sidelink positioning, To send instructions for reverse link communication from each UE in the group to each other UE in the group, To receive instructions for reverse link communication from each of the other UEs in the group to each of the other UEs, A method comprising determining a group status instruction for at least one UE in the group based on the instruction for reverse link communication from each UE in the group to the UE and the instruction for reverse link communication from each UE in the group to each of the other UEs in the group, wherein the group status instruction for the at least one UE indicates that the group includes the at least one UE or that the group excludes the at least one UE.

2. The method according to claim 1, wherein sending the instruction for reverse link communication to each of the other UEs in the group and receiving the instruction for reverse link communication from each of the other UEs in the group is based on SL multicast when the group includes three or more UEs.

3. The method according to claim 1, wherein an instruction for reverse link communication from any UE in the group to any other UE in the group indicates whether or not SL positioning protocol (SLPP) signaling transmitted by the any UE was received by the any other UE, and the SLPP signaling preferably includes an SLPP message, an SL positioning reference signal (PRS), or both.

4. The method according to claim 1, wherein when the group status indication of the at least one UE indicates that the group includes the at least one UE, the at least one UE is included in the group, and when the group status indication of the at least one UE indicates that the group excludes the at least one UE from the group, the at least one UE is excluded from the group.

5. The method according to claim 1, wherein each of the other UEs in the group determines the group status instruction for the at least one UE based on instructions of reverse link communication received from the other UEs in the group, and the at least one UE is included in or excluded from the group based on the group status instruction for the at least one UE determined by each of the UEs in the group.

6. The status of forward link communication and reverse link communication between all pairs of UEs in the group is determined based on the instructions for reverse link communication from each UE in the group to each of the other UEs in the group, The method according to claim 1, further comprising determining the group status indication for the at least one UE based on the status of the forward link communication and the status of the reverse link communication between all pairs of UEs in the group.

7. The method according to claim 6, wherein the status of forward link communication and the status of reverse link communication between any pair of UEs in the group indicate, for each of the forward and reverse transfer directions, whether successful SLPP signaling transfer between the pair of UEs is currently possible, currently impossible, or has an unknown status.

8. The method according to claim 1, wherein the instruction for reverse link communication is an implicit instruction, and when the second UE reports one or more measurements taken by the second UE for a sidelink PRS transmitted by the first UE, it is assumed that reverse link communication from the first UE to the second UE exists; and when the second UE does not report any measurements taken by the second UE for a sidelink PRS transmitted by the first UE, or when the second UE provides an instruction that it was not possible to take any measurements for an SL PRS transmitted by the first UE, it is assumed that reverse link communication from the first UE to the second UE does not exist.

9. A user device (UE) configured to enable a group of UEs, including the UE, to perform sidelink positioning. A wireless transceiver configured to communicate wirelessly with a network entity, At least one memory, The system comprises the wireless transceiver and at least one processor coupled to the at least one memory, wherein the at least one processor is Through the wire transceiver, an instruction for reverse link communication from each UE in the group to the UE is sent to each of the other UEs in the group. The wire transceiver receives instructions for reverse link communication from each of the other UEs in the group to each of the other UEs in the group, A group status instruction for at least one UE in the group is determined based on the instruction for reverse link communication from each UE in the group to the UE and the instruction for reverse link communication from each UE in the group to each of the other UEs in the group, wherein the group status instruction for at least one UE indicates that the group includes the at least one UE or excludes the at least one UE from the group.

10. The UE according to claim 9, wherein the at least one processor is configured to, when the group includes three or more UEs, send the instructions for reverse link communication to each of the other UEs in the group and receive the instructions for reverse link communication from each of the other UEs in the group, based on SL multicast.

11. An instruction for reverse link communication from any UE in the group to any other UE in the group indicates whether or not SL positioning protocol (SLPP) signaling transmitted by the any UE was received by the any other UE, wherein the SLPP signaling preferably includes an SLPP message, an SL positioning reference signal (PRS), or both, according to claim 9.

12. The UE according to claim 9, wherein when the group status indication of the at least one UE indicates that the group includes the at least one UE, the at least one UE is included in the group, and when the group status indication of the at least one UE indicates that the group excludes the at least one UE from the group, the at least one UE is excluded from the group.

13. The UE according to claim 9, wherein each of the other UEs in the group determines the group status instruction for the at least one UE based on instructions of reverse link communication received from the other UEs in the group, and the at least one UE is included in or excluded from the group based on the group status instruction for the at least one UE determined by each of the UEs in the group.

14. The aforementioned at least one processor is The status of forward link communication and reverse link communication between all pairs of UEs in the group is determined based on the instructions for reverse link communication from each UE in the group to each of the other UEs in the group, The group status indication for at least one UE is determined based on the status of the forward link communication and the status of the reverse link communication between all pairs of UEs in the group. The UE according to claim 9, wherein the status of forward link communication and the status of reverse link communication between any pair of UEs in the group can indicate, for each of the forward and reverse transfer directions, whether successful SLPP signaling transfer between the pair of UEs is currently possible, currently impossible, or has an unknown status.

15. The UE according to claim 9, wherein the instruction for reverse link communication is an implicit instruction, and when the second UE reports one or more measurements obtained by the second UE for a sidelink PRS transmitted by the first UE, it is assumed that reverse link communication from the first UE to the second UE exists; and when the second UE does not report any measurements obtained by the second UE for a sidelink PRS transmitted by the first UE, or when the second UE provides an instruction that it was not possible to obtain any measurements for an SL PRS transmitted by the first UE, it is assumed that reverse link communication from the first UE to the second UE does not exist.

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